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PubMed1999

In vitro nitric oxide effects on basal and gonadotropin-releasing hormone-induced gonadotropin secretion by pituitary gland of male crested newt (Triturus carnifex) during the annual reproductive cycle.

The objective of this study was to test the possible nitric oxide (NO) involvement in pituitary gonadotropin secretion in the male crested newt, Triturus carnifex. Pituitaries were incubated in vitro with medium alone, GnRH, NO donor (NOd, sodium nitroprusside), NO synthase inhibitor (NOSi, Nomega-nitro-L-arginine methyl ester), cGMP analogue (cGMPa, 8-bromo-cGMP), soluble guanylate cyclase inhibitor (sGCi, cystamine), GnRH plus NOSi, GnRH plus sGCi, and NOd plus sGCi during the annual reproductive cycle: pre-reproduction, reproduction (noncourtship and courtship), and the refractory, recovery, and estivation periods. To determine pituitary gonadotropin secretion indirectly, newt testes were superfused in vitro with preincubated pituitaries, and androgen release was determined. NO synthase (NOS) activity and cGMP levels were assessed in the preincubated pituitaries. Medium alone- and GnRH-preincubated pituitary increased androgen secretion during pre-reproduction, noncourtship, courtship, and recovery; the GnRH-induced increase was higher than the medium alone-induced increase during pre-reproduction, noncourtship, and recovery. NOd and cGMPa increased androgens in all reproductive phases considered except courtship; the NOd- and cGMP-induced increase was higher than the medium alone-induced increase during pre-reproduction, noncourtship, and recovery. NOS activity was highest during courtship and lowest during the refractory and estivation periods. GnRH increased NOS activity during pre-reproduction, noncourtship, and recovery. Cyclic GMP levels were highest during courtship and lowest during the refractory period and estivation. GnRH increased cGMP levels during pre-reproduction, noncourtship, and recovery, while NOd did so during all reproductive phases considered. These results suggest that basal and GnRH-induced gonadotropin secretion are up-regulated by NO in the pituitary gland of the male Triturus carnifex.

Androgens↗

PubMed2004

Survival costs of reproduction in the blue tit (Parus caeruleus): a role for blood parasites?

One of the central tenets in life-history theory is that there is a trade-off between current and future reproduction (i.e. a cost of reproduction). The mechanism for this cost of reproduction is, however, largely unknown. One hypothesis is that the high workload during reproduction compromises resistance to parasites and that the resulting increase in parasitaemia has negative effects on the prospects of future survival. Although empirical evidence for a negative relationship between reproductive effort and parasite resistance exists, the causal relationships between reproductive effort, parasite resistance and future reproduction are still unclear. We use a path analytical approach to investigate whether a change in parasite resistance (as measured by intensities of infections by the blood parasite Haemoproteus) after manipulation of reproductive effort, translates into altered survival in female blue tits. Our results show a negative relationship between reproductive effort and parasite resistance, although evident only in first-year breeders. Moreover, we found survival costs of reproduction in first-year breeders. These costs were, however, not mediated by the blood parasite studied.

Analysis of Variance↗

PubMed2006

Response to intensity of reproduction in mouse lines resistant or susceptible to fescue toxicosis.

Our objective was to examine whether mouse lines divergently selected for response to fescue toxicosis differed in the impact of increasing reproductive intensity on growth, final weight or first and second parity reproduction. Resistant (R) and susceptible (S) females were never mated (NR), mated only once (low reproduction, LR), mated after their first litter was weaned (moderate reproduction, MR) or paired continuously with a male (high reproduction, HR), allowing concurrent pregnancy and lactation. Final weight was significantly higher in mated than in not mated females (31.6 +/- 0.6, 35.9 +/- 0.6, 36.8 +/- 0.6 and 37.2 +/- 0.5 g for NR, LR, MR and HR females respectively), but the effect of increasing reproductive intensity was similar in both lines. Neither genetic line, reproductive treatment (LR and MR versus HR) nor their interaction affected first parity traits of dams or pups. In second parity, S dams produced larger litters at birth and weaning and heavier litters at birth than R dams, and MR dams produced more pups and heavier litters than HR dams. As with first litters, however, line by reproductive treatment interactions were not significant or important. Concurrent pregnancy and lactation (the HR treatment) had a similar dampening impact on the expected increase in litter size between first and second parity of both lines. Thus, lines divergently selected for toxicosis response did not differ significantly in the impact of increasing reproductive intensity on dam or pup growth, reproductive output through two parities or mature size. This conclusion should not be generalized. Selection responses in livestock should be monitored to ensure that improvement in one trait does not lead to deterioration in others.

Animals↗

PubMed2006

Changing their minds with time: a comparison of hypothetical and actual reproductive behaviors in parents of children with cystic fibrosis.

OBJECTIVE: Newborn screening for cystic fibrosis, with appropriate counseling, enables carrier parents to be informed early about future reproductive choices. Previous studies have assessed attitudes toward reproductive decisions in a hypothetical pregnancy or have measured reproductive behaviors. We aimed to measure parent attitudes to reproductive technologies and to compare prospectively these attitudes with later reproductive behaviors. METHODS: Parents of children who had cystic fibrosis and were aged 2 to 7 years were surveyed at baseline using a written questionnaire that explored attitudes to prenatal testing and termination of pregnancy in a hypothetical pregnancy. Parent knowledge and access to genetic counseling services also were assessed. Five years later, we compared attitudes with actual reproductive behaviors. RESULTS: Fifty-six mothers participated at baseline, and 43 were resurveyed 5 years later. Parent knowledge of cystic fibrosis and genetics was very good. A total of 93% had met a genetic counselor at the time of diagnosis, and more than half had on at least 1 subsequent occasion. At baseline, 82% reported that they would be likely to have prenatal diagnosis in a subsequent pregnancy, and 56% reported that they would be likely to terminate an affected pregnancy. Twenty-seven mothers since had been pregnant, with prenatal diagnosis used in 33 of the 55 pregnancies. In 67%, the hypothetically reported behavior regarding use of prenatal testing was the same as their actual behavior. Five of the 33 tested pregnancies were affected; all ended in termination. Reproductive choices in relationship to the number of children wanted, together with attitudes toward prenatal diagnosis and termination of pregnancy, were dynamic over time, with decisions having changed in both directions. CONCLUSIONS: This cohort of parents has actively used reproductive technologies since the birth of a child who has cystic fibrosis that was diagnosed by newborn screening. The dynamic aspect of reproductive choices highlights the importance of ongoing access to genetic counseling beyond the initial period of diagnosis and education, regardless of whether parents report that they expect to use reproductive technologies.

Abortion, Induced↗

PubMedDate not supplied

Adolescents' reports of reproductive health education, 1988 and 1995.

CONTEXT: Reproductive health education is a key strategy for promoting safe sexual behavior among teenagers. In the last decade, new initiatives in response to AIDS and growing interest in abstinence education may have changed the prevalence, content or timing of the reproductive health education provided by schools and parents. METHODS: Formal reproductive health education and communication with parents about reproductive health among males aged 15-19 were analyzed using data from the 1988 and 1995 National Surveys of Adolescent Males. Young men's reports of formal instruction were compared with reports by adolescent females from the 1995 National Survey of Family Growth. RESULTS: Between 1988 and 1995, formal reproductive health education became nearly universal among adolescent males: In 1988, 93% of teenage males received some formal instruction, compared with 98% in 1995. The percentage of teenage males who received instruction about AIDS increased from 73% to 97% and the proportion who received instruction about how to say no to sex increased from 58% to 75%. Adolescent males who had dropped out of school received significantly less reproductive health education than those who had stayed in school, however. In addition, the median age at initial instruction decreased from age 14 to 13. Many males did not receive instruction prior to first intercourse, with non-Hispanic blacks being significantly less likely than other males to receive education prior to first intercourse. In 1995, 54% of black males had received reproductive health education before they first had sex, compared with 68% of Hispanic males and 76% of non-Hispanic white males. A smaller share of adolescent males than females received reproductive health education, and males were less likely than females to receive instruction prior to first intercourse. CONCLUSIONS: During the last decade, many types of formal reproductive health education for adolescents expanded. Further efforts should focus on assuring access to timely, comprehensive and high-quality reproductive health education for all teenagers and reducing gaps in access related to race, gender and school attendance.

Acquired Immunodeficiency Syndrome↗

PubMed2004

[Effect of restorative measures on quantitative characters of reproduction for Leynrus chinensis population in the degenerated grassland].

Studies on the reproductive characters of Leymus chinensis population in two plots showed that the density of L. chinensis population declined significantly in plowing plot, while the density of reproductive tillers varied insignificantly. The reproductive tiller had longer ear, longer inter-node, higher ratio of reproductive growth, higher seeding percentage, more ear-nodes, more spikelets, more florets and grains in plowing plot than in enclosing plot. The grain yield, net weight of grain, and the weight of 1000 grains was 2.68 times, 3.49 times and 1.3 times higher in plowing plot than in enclosing plot, respectively. The reproductive tillers with double-spikelet were 16% more in plowing plot than in enclosing plot, and they developed more double-spikelets. Relatively, the reproductive tiller in plowing plot developed few double-spikelets, more florets and more grains, so that, the grain yield of the population was enhanced largely. The reproductive allocations of L. chinensis didn't response differently to both plowing and enclosing at three module levels, including population to reproductive tiller, reproductive tiller to ear, and ear to grain, but the allocation of population to ear and to grain, and the allocation of reproductive tiller to grain were significantly higher in plowing plot than in enclosing plot.

Biomass↗

PubMed2003

Legal forms and reproductive norms.

This article draws on Pashukanis's concept of legal form and on O'Brien's concept of synthetic value to argue that legal form plays a role in reproductive relations by constructing legal subjects as the bearers of reproductive responsibilities. Pashukanis conceived of legal form as playing a particular role in capitalist exchange relations by interpellating subjects as the bearers of property rights. O'Brien argued that reproduction's specific value is synthetic value, which represents the value of integrating nature and reason in species continuity. Synthetic value is distinct from exchange value or emotional value which may also attach to reproductive process. By working through Pashukanis's method of extracting legal form from specific social relations and by adapting it to reproductive relations, an example is provided of how legal form analysis can be extended beyond the particular context of capitalist exchange relations. Just as legal form constitutes owners and non-owners as legal subjects, so it constitutes reproducers and non-reproducers. By tracing the way in which law attributes reproductive responsibility, legal form analysis shows us how law draws a line between wanting to attribute responsibility and not to attribute it, and this contradiction is a hook which social forces such as sexuality, gender, race, class and disability can latch on to in pushing legal form to shape reproductive responsibilities in a particular way. Each legal form is also externally contradicted by other legal forms. When law negotiates a balance between the reproductive norms of responsibilities and rights, it demonstrates how particular legal forms manage the interaction of different sets of social relations, such as reproduction and exchange.

Capitalism↗

PubMed2001

Seasonal changes of reproductive behavior and fecal steroid concentrations in Père David's deer.

From July 1997 to September 1997 and from March 1998 to July 1998, we studied reproductive behaviors of Père David's deer in Dafeng, China. During the field behavioral observations, we collected fresh voided fecal samples from the Père David's stags and hinds periodically and kept those samples under -20 degrees C until laboratory analysis. We analyzed the fecal testosterone, estradiol, and progesterone concentrations in those samples using radioimmunoassay. During this study, we also recorded 17 types of male reproductive behaviors and nine types of female reproductive behaviors. Reproductive behaviors and the fecal steroid concentrations showed overt seasonal fluctuations. There were statistically significant correlations between some male reproductive behaviors, such as anogenital sniffing, urine sniffing, urine spraying, wallowing, bellowing, antler adorning, Antler swags mud, chasing, herding hinds, chin resting, mounting and copulating, with the fecal testosterone concentrations. These results suggested that seasonal reproductive behaviors in stags are strongly associated with circulating testosterone. We also found that some female reproductive behaviors fluctuate corresponding with changes in fecal estrogen concentrations. Although there was no direct evidence to confirm the correlations between female reproductive behaviors and fecal estrogen in our experiment, we could not rule out that reproductive activities of hinds were largely related to ovarian estrogen secretion, and estrogen is necessary for inducing female reproductive behaviors.

Acclimatization↗

PubMed2006

Phenotypic plasticity of reproductive traits in response to food availability and photoperiod in white-footed mice (Peromyscus leucopus).

Although most temperate-zone mammals are seasonal breeders, many populations display variation in winter reproductive phenotype. For most mammals, the primary environmental cues regulating reproductive status are food availability and photoperiod, and these two factors can interact in their effect. Low food availability is primarily thought to suppress reproduction by reducing body mass and thereby forcing energy allocations to survival alone. However, because most small mammals rely on an increase in food intake rather than stored nutrients for reproduction, we hypothesized that food availability could act as a signal for low resource availability and affect reproduction even when body condition was not affected. We tested the prediction that restricted food access, without reduced body mass, could alter reproductive responses to short photoperiod. We used genetically distinct lines of white-footed mice (Peromyscus leucopus) derived from a wild population with genetic variation in the neuroendocrine pathway that regulates reproduction in response to environmental cues. The lines were created by artificial selection on gonad size in short photoperiods. Individuals from one line strongly suppress gonadal development in response to short photoperiods, while individuals from the other line suppress gonadal development weakly or not at all. Unresponsive individuals from the selected and an unselected control line were exposed to an intermittent food access protocol that did not affect body mass and only slightly reduced total food intake. We found that restricting food access caused reproductive suppression in short photoperiods but not long photoperiods, with no decrease in body mass. These results provide evidence for an interaction between food and photoperiod that is not dependent upon body condition or energy balance. The results also demonstrate plasticity in the reproductive response to photoperiod of otherwise reproductively nonphotoperiodic white-footed mice.

Analysis of Variance↗

PubMed2006

Does adrenal responsiveness vary with sex and reproductive status in Egernia whitii, a viviparous skink?

In mammals, oestrogens generally stimulate adrenal function whilst androgens are inhibitory, and gestating females down-regulate their acute response to stressors in order to protect current reproductive investment. This study aimed to determine if adrenocortical function is similarly modulated by sex and reproductive status in the viviparous lizard, Egernia whitii. We compared the adrenocortical response to acute capture stress in female E. whitii during active (post-ovulatory and gestating) and quiescent (post-partum) phases of their reproductive cycle. We also compared the responses of reproductively quiescent males and females to acute stress and ACTH challenge to determine if there are sex-related differences in HPA axis activity when the influence of reproductive hormones is minimal. The females' responses to acute capture stress varied significantly with reproductive stage, and quiescent females displayed the strongest immediate response, with a rapid and sustained increase in plasma corticosterone (CORT) concentrations. Post-ovulatory females showed the most conservative adrenocortical response and while gestating females showed a large immediate response, this was not as prolonged as in quiescent females. Reproductively quiescent males and females exhibited similar responses to acute stress, and also responded similarly to ACTH injection, with plasma CORT reaching maximal concentrations of 52.1 and 59.4 ng/mL, respectively. Reproductively quiescent females treated with oestrogen exhibited greater responsiveness to ACTH than control females, although basal plasma CORT concentrations were unaltered: these results suggest that the attenuation of the acute stress response observed in reproductively active females of E. whitii may be regulated upstream of ACTH secretion. Our results demonstrate that the activity of the HPA axis is modulated by reproductive status in this viviparous reptile, and that gestating females are able to buffer their embryos from the potentially adverse effects of elevated plasma corticosteroids.

Adrenal Cortex↗

PubMed2001

The burden of reproductive-organ disease in rural women in The Gambia, West Africa.

BACKGROUND: Data on the epidemiology of reproductive-organ morbidity are needed to guide effective interventions, to set health-care priorities, and to target future research. This study aimed to find out the prevalence of reproductive-organ disease in a sample of rural Gambian women. METHODS: A questionnaire on reproductive health was administered by fieldworkers to women aged 15-54 years living in a rural area under demographic surveillance. A female gynaecologist questioned and examined the women (including speculum and bimanual pelvic examinations). Vaginal swabs were taken to test for Trichomonas vaginalis, Candida albicans, and bacterial vaginosis, cervical smears for cytology, cervical swabs for Chlamydia trachomatis PCR and Neisseria gonorrhoeae culture, and venous blood for haemoglobin, HIV, herpes simplex virus 2, and syphilis serology. FINDINGS: 1348 (72.0%) of 1871 eligible women took part. Reproductive-organ symptoms were more likely to be reported to the gynaecologist (52.7% of women) than to the fieldworker (26.5%). Menstrual problems, abnormal vaginal discharge, and vaginal itching were the most commonly reported symptoms. A minority of women said they had sought health care for their symptoms. The frequencies of reproductive-organ morbidity were high: menstrual dysfunction 34.1% (95% CI 29.6-39.1), infertility 9.8% (8.2-11.6), reproductive-tract infections 47.3% (43.7-51.0), pelvic tenderness 9.8% ((7.0-13.5), cervical dysplasia 6.7% (5.2-8.4), masses 15.9% (12.5-20.1), and childbirth-related damage to pelvic structures 46.1% (40.1-52.3). 948 (70.3%) women had at least one reproductive-organ disorder. INTERPRETATION: For these rural women, whose lives depend heavily on their reproductive function, reproductive-organ disease is a large burden. In inadequately resourced rural areas, with poor education, heavy agricultural and domestic labour, and limited access to quality health care, many women are not able to attain and maintain reproductive health and wellbeing.

Adolescent↗

PubMed2001

Effects of neonatal exposure to a high-dose p-tert-octylphenol on the male reproductive tract in rats.

Time-course alterations in morphological changes of the reproductive tract including spermatogenesis as well as pituitary and gonadal hormones, reproductive ability, and the size of the sexually dimorphic nucleus of the preoptic area (SDN-POA) were investigated in male rats neonatally exposed to 100 mg/kg p-tert-octylphenol (OP) subcutaneously. OP treatment affected hormone levels of follicle stimulating hormone (FSH) and testosterone, reproductive organ weights and sperm counts. Slightly depressed FSH levels at prepuberty and prolonged suppression of testosterone till 7 weeks of age were observed as two hormonal alterations. The lasting reduction in testosterone appeared to be associated with growth inhibition of male reproductive organs such as the testis, prostate and epididymis, these demonstrating low organ weights compared with those of age-matched controls till 7 weeks of age. The FSH concentrations after puberty showed a rise to values equal to or higher than those of the control group, suggesting recovery of maturation of the reproductive tract. No morphological abnormalities, even with morphometric stage analysis of spermatogenesis, were detected in the male reproductive tract throughout the study. Size of the SDN-POA and reproductive ability was comparable to those in controls. At the termination (18 weeks of age), however, a reduction in the sperm count in the epididymis of OP-treated animals demonstrated a possibility that the male reproductive system might be still affected by neonatal exposure to OP. The results observed demonstrate that neonatal exposure to a high-dose OP exerts estrogenic action directly or indirectly, resulting in slight but prolonged impairment of the male reproductive tract. The suppression of FSH caused by modulation of the hypothalamus-pituitary control system may be the trigger for the impairment, while the possibility of direct estrogenic action of OP is not ruled out. Our results also indicate that more sensitive endpoints should be established to detect the effects of neonatal exposure to estrogens or estrogenic compounds on the male reproductive tract.

Animals↗

PubMedDate not supplied

Reproductive pattern in consanguineous and non-consanguineous marriages in La Cabrera, Spain.

BACKGROUND: Among determinants of the structure of human populations, consanguineous marriages can be useful in determining to what extent they influence the genetic structure of the population. This knowledge may be gained by comparing the reproductive performance of related and non-related couples. The population studied, La Cabrera, is a mountainous region in the Leon province (north-western Spain). It includes four neighbouring municipalities with similar geographic, climatic and ecological features with 37 parishes occupying an area of 784.2 km(2), of which only 1.5% is arable. The number of inhabitants remained stable from 1887 (9526 inhabitants) to 1960 (8984), when due to emigration it began to decrease. The average inbreeding coefficient (alpha) for the period 1880-1989 (up to third degree) was 4.82 x 10(-3). AIM: The objective of this analysis was to evaluate the possible factors determining the differences between consanguineous and non-consanguineous families residing in La Cabrera during the period 1880-1959. SUBJECTS AND METHODS: To study the structure and dynamics of each couple, families were reconstituted for the period 1880-1959 using demographic data corresponding to births, deaths and marriages obtained from parish registers. This procedure provided information on each couple's reproductive history through information concerning the mates' deaths as well as their offspring's births and deaths. Principal component analysis revealed the existence of three factors that together explained 57% of the reproductive pattern variability of La Cabrera. RESULTS: The first component (eigenvalue: 3.56) correlated positively with the number of live births and with the duration of the reproductive period. Component II (eigenvalue: 1.54) had a positive correlation with variables describing the beginning of the marital union, and with those indicating its ending. Finally, component III (eigenvalue: 1.13) reflected a negative association with the two variables that described neonatal and post-neonatal mortality. The above demographic variables represented the reproductive process in La Cabrera adequately. Fertility was the variable that offered the best explanation of the reproductive pattern (32%), followed by the marital structure (13%) and the infant mortality (12%). CONCLUSION: In the La Cabrera population, consanguinity appears as a socio-cultural process that affects the reproductive dynamic. Consanguinity modifies the marital structure and alters the reproductive pattern, prolonging the reproductive period, which results in a greater number of offspring. Lower infertility rates and the possible compensatory effect for infant mortality may reflect biological factors making the wife's reproductive period more efficient.

Adult↗

PubMed2004

Male Reproductive Health: A village based study of camp attenders in rural India.

BACKGROUND: A paucity of information about male reproductive health and a perceived interest in involvement among local men provided the impetus for carrying out a village based male reproductive health camp. The aim was to investigate men's willingness to participate in such camps, and to describe reproductive health problems in men. METHODS: Structured interviews were carried out with 120 men attending a reproductive health check-up in a village in rural West Bengal, India. General information, details of family planning methods used and data on reproductive health complaints were collected. Clinical examinations were also carried out. Socio-demographic characteristics were compared for men with and without reproductive health and urinary complaints. RESULTS: Three quarters of the married men were using contraception, but the majority stated that their wives were responsible for it. The most common reproductive health complaint was urinary problems; 28% had burning on urination, and 22% reported frequent and/or difficult urination. There were few social or demographic differences between men with and without problems. Seventeen percent of the men had clinically diagnosed reproductive health problems, the most common being urethral discharge. None of the men with diagnosed problems were using condoms. CONCLUSIONS: This study highlights the interest of men in their reproductive health, but also highlights the high proportion of men with problems. In addition, a number of men with clinically diagnosed problems had not reported them in the interviews, illustrating either the reticence to report or the lack of knowledge about symptoms of reproductive health problems. Recommendations for future programmes and research in this field are given.

Journal Article↗

PubMed1994

Investigation of numbers and motility of spermatozoa in reproductively active and socially suppressed males of two eusocial African mole-rats, the naked mole-rat (Heterocephalus glaber) and the Damaraland mole-rat (Cryptomys damarensis).

Reproductive tracts and spermatozoa from reproductively active and reproductively suppressed non-breeding males from two species of eusocial African mole-rats Cryptomys damarensis and Heterocephalus glaber were examined. In two captive colonies of Heterocephalus glaber, reproductive tracts from seven non-breeding males removed from their colonies, and housed singly for 5-6 weeks to cause reproductive activation, were compared with reproductive tracts from seven non-breeding males. The body weight of the separated, reproductively active males increased significantly (P < 0.01), and the mean testis weights relative to body weight of the reproductively active males were significantly larger (P < 0.05) than those of non-breeding males. The number of spermatozoa, in one half of the reproductive tract, was higher in active males than in non-breeding males (mean +/- SEM: 8.59 x 10(6) +/- 2.69 x 10(6) versus 1.78 x 10(6) +/- 1.43 x 10(6), respectively; P < 0.05). In addition, six of the seven reproductively active males, but only two of seven non-breeding males, had motile spermatozoa. A total of 28 wild Cryptomys damarensis from two colonies were examined in the field. The testis weights relative to body weight of breeding males (n = 7) were higher than those of non-breeding males (n = 19; P < 0.01), but the number of spermatozoa did not differ significantly between the two groups (0.13 x 10(6) +/- 0.06 x 10(6), n = 7 versus 0.29 x 10(6) +/- 0.14 x 10(6), n = 21, respectively). Breeding and non-breeding males produced similar numbers of motile spermatozoa.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2003

NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Di-n-Hexyl Phthalate (DnHP).

The National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for di-n-hexyl phthalate (DnHP) to cause adverse effects on reproduction and development in humans. DnHP is one of 7 phthalate chemicals evaluated by the NTP CERHR Phthalates Expert Panel. These phthalates were selected for evaluation because of high production volume, extent of human exposures, use in children's products, and/or published evidence of reproductive or developmental toxicity. Available information indicates that DnHP is manufactured in relatively small amounts but occurs in a variety of commercial products including dip-molded products such as tool handles or dishwasher baskets, flooring, vinyl gloves, flea collars, and conveyer belts used in food processing. The results of this evaluation on DnHP are published in an NTP-CERHR monograph which includes: 1) the NTP Brief, 2) the Expert Panel Report on the Reproductive and Developmental Toxicity of DnHP, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to DnHP on human development and reproduction. The scientific evidence was insufficient to reach a conclusion regarding the potential for DnHP to adversely affect human development or reproduction. There was very limited information on developmental and reproductive toxicity available to the panel. The panel evaluated only a single developmental toxicity study using a high dose (9,900 mg/kg body weight/day on gestational days 6-13) of DnHP. No live pups were delivered. In a reproductive study, effects on fertility were noted in all treatment groups (380-1,670 mg/ kg body weight/day). These studies provided sufficient information in experimental animals to conclude that DnHP is a reproductive and developmental toxicant at the doses tested. However, the treatment doses were high and these studies did not determine an exposure level at which no adverse effects occur. Human exposure information for DnHP was not available to the panel. However, the panel assumed that the US general population would be exposed to 3-30 mug/kg body weight/day, based upon the range of estimated exposures for DEHP, a more widely used phthalate. Thus, considering the inadequate quantitative information from the experimental animal studies and the inadequate human exposure data, the panel concluded there is insufficient information to reach a conclusion of the potential for DnHP to adversely affect human development or reproduction. NTP-CERHR monographs are transmitted to federal and state agencies, interested parties, and the public and are available in electronic PDF format on the CERHR web site (http://cerhr.niehs.nih.gov) and in printed text or CD-ROM from the CERHR (National Institute of Environmental Health Sciences, P.O. Box 12233, MD EC-32, Research Triangle Park, NC; fax: 919-316-4511).

Journal Article↗

PubMed2003

NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Di-n-Butyl Phthalate (DBP).

TThe National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for di-n-butyl phthalate (DBP) to cause adverse effects on reproduction and development in humans. DBP is one of 7 phthalate chemicals evaluated by the NTP CERHR Phthalates Expert Panel. These phthalates were selected for evaluation because of high production volume, extent of human exposures, use in children's products, and/or published evidence of reproductive or developmental toxicity. Unlike many phthalates, DBP is not currently used as a plasticizer in polyvinyl chloride plastics. DBP is a component of latex adhesives and is used in cosmetics and other personal care products, as a plasticizer in cellulose plastics, and as a solvent for dyes. The results of this evaluation on DBP are published in a NTP-CERHR monograph which includes: 1) the NTP Brief, 2) the Expert Panel Report on the Reproductive and Developmental Toxicity of Di-n-Butyl Phthalate, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to DBP on human development and reproduction. First, although DBP could possibly affect human reproduction and development if exposures are sufficiently high, the NTP concludes that there is negligible concern for reproductive toxicity in exposed adults. Second, the NTP concludes that there is minimal concern for developmental effects when pregnant women are exposed to DBP levels estimated by the panel (2-10 mug/kg body weight/day). There is no direct evidence that exposure of people to DBP adversely affects reproduction or development, but studies reviewed by the expert panel show that oral exposure to high doses of DBP (>/=100 mg/kg body weight/day) may adversely affect the prenatal and early postnatal development in rodents. Finally, based on exposure estimates in women of reproductive age, the NTP concludes that there is some concern for DBP causing adverse effects to human development, particularly development of the male reproductive system. NTP-CERHR monographs are transmitted to federal and state agencies, interested parties, and the public and are available electronically in PDF format on the CERHR web site (http://cerhr.niehs.nih.gov) and in printed text or CD-ROM from the CERHR (National Institute of Environmental Health Sciences, P.O. Box 12233, MD EC-32, Research Triangle Park, NC; fax: 919-316-4511).

Journal Article↗

PubMed2003

NTP-CERHR Monograph on the Potential Human Reproductive and Developmental Effects of Butyl Benzyl Phthalate (BBP).

The National Toxicology Program (NTP) Center for the Evaluation of Risks to Human Reproduction (CERHR) conducted an evaluation of the potential for butyl benzyl phthalate (BBP) to cause adverse effects on reproduction and development in humans. BBP is one of 7 phthalate chemicals evaluated by the NTP CERHR Phthalates Expert Panel. These phthalates were selected for evaluation because of high production volume, extent of human exposures, use in children's products, and/or published evidence of reproductive or developmental toxicity. BBP is used in the production of vinyl tiles and polyvinyl chloride (PVC) to make products such as food conveyor belts, carpet tile, tarps, artificial leather, automotive trim, and traffic cones. The results of this evaluation on BBP are published in a NTP-CERHR monograph which includes: 1) the NTP Brief, 2) the Expert Panel Report on the Reproductive and Developmental Toxicity of Butyl Benzyl Phthalate, and 3) public comments received on the Expert Panel Report. As stated in the NTP Brief, the NTP reached the following conclusions regarding the possible effects of exposure to BBP on human development and reproduction. First, the NTP concludes there is negligible concern for adverse reproductive effects in exposed men. Data are insufficient to reach a conclusion on possible eproductive effects in exposed women. There is no direct evidence that exposure of people to BBP adversely affects reproduction or development, but studies reviewed by the expert panel show that oral exposure of laboratory animals to high doses (>/=1000 mg/kg body weight/day) of BBP can adversely affect development, including development of the male reproductive tract. Second, the NTP concludes that there is minimal concern for developmental effects in fetuses and children. Evidence showed adverse reproductive effects in rats at doses of 100 mg/kg body weight/day, but not at 20 mg/kg/day. Exposure estimates for women of reproductive age were estimated to be 7.8 mug/kg body weight/day. Therefore, this estimated exposure is at least 2,500-to 25,000- fold lower than the toxic dose in rats. NTP-CERHR monographs are transmitted to federal and state agencies, interested parties, and the public and are available in electronic PDF format on the CERHR web site (http://cerhr.niehs.nih.gov) and in printed text or CD-ROM from the CERHR (National Institute of Environmental Health Sciences, P.O. Box 12233, MD EC-32, Research Triangle Park, NC; fax: 919-316-4511).

Journal Article↗