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PubMedDate not supplied

Exposure to different spectra of light, continuous light and treatment with melatonin affect reproduction in the Indian desert gerbil Meriones hurrianae (Jerdon).

In two separate experiments, the gonadal response to melatonin treatment and exposure to continuous white light (LL) and different spectra of light (blue, green, yellow and red) was investigated in the Indian desert gerbil Meriones hurrianae. In experiment 1, exposure to green light for 8 weeks increased (p < 0.01) the gonadosomatic index (GSI) and sperm count, whereas exposure to red light decreased (p < 0.01) the GSI and sperm count. The response of accessory organs to the treatment varied. In experiment 2, exposure to LL for 5 weeks decreased the GSI and sperm count, and treatment with melatonin (in the late-light period) not only increased the GSI and sperm count, but also counteracted the inhibitory action of LL and red light. Melatonin treatment stimulated accessory sex organs and the scent gland surface area. The inhibition or stimulation of the reproductive parameters correlated with an increase or decrease in pinealocytes and pinealocyte nuclear diameters. Therefore, the influence of light and its spectra on reproduction may be mediated by the pineal gland, though extrapineal mechanisms cannot be ruled out.

Animals↗

PubMed2005

Relating results of chronic toxicity responses to population-level effects: modeling effects on wild Chinook salmon populations.

Standard toxicity tests assess the physiological responses of individual organisms to exposure to toxic substances under controlled conditions. Time and space restrictions often prohibit the assessment of population-level responses to a toxic substance. Compounds affecting various toxicity endpoints, such as growth, fecundity, behavior, or immune function, alter different demographic traits and produce different impacts on the population. Chronic effects of immune suppression, reproductive impairment, and growth reduction were examined using life history models for Chinook salmon (Oncorhynchus tshawytscha). Modeled immune suppression acted through reductions in age-specific survival, with first- and second-year survival producing the greatest changes in the population growth rate (lamda). A 10% reduction in various reproductive parameters all produced a similar lamda, but different sensitivity and stable age distributions. Growth reduction models incorporated effects to both survival and reproduction and produced additive effects. Overall, model output indicated that for Chinook salmon, alteration of first-year survival has the greatest relative impact on lamda. Results support the importance of linking toxicity endpoints to the demographic traits that they influence and help generate toxicity tests that are more relevant for the species. Life history modeling provides a useful tool to develop testable hypotheses regarding specific and comparative population-level impacts.

Animals↗

PubMed2002

Modelling population dynamics of Orius laevigatus and O. albidipennis (Hemiptera: Anthocoridae) to optimize their use as biological control agents of Frankliniella occidentalis (Thysanoptera: Thripidae).

ORIUS LAEVIGATUS: (Fieber) and O. albidipennis (Reuter) play an important role in the control of Frankliniella occidentalis (Pergande) in crops and natural vegetation in the Mediterranean area. The biological parameters of the two anthocorids were studied and modelled in relation to temperature to optimize their use in thrips control programmes. Development times and reproductive parameters of O. laevigatus and O. albidipennis were determined at 20, 25, 30 and 35 degrees C. Pre-imaginal development times ranged from 34.6 and 37.2 days at 20 degrees C to 12.3 and 10.2 days at 35 degrees C in O. laevigatus and O. albidipennis, respectively. The lower thermal development threshold was significantly higher for O. albidipennis (14.2 +/- 0.9 degrees C) than for O. laevigatus (11.3 +/- 0.7 degrees C). No significant differences in fecundities between the two anthocorids were observed at 20, 25 and 30 degrees C. At 35 degrees C, O. albidipennis had a significantly higher fecundity than O. laevigatus. Non-linear models were used to explain reproduction and female survivorship in relation to temperature. The upper reproductive thresholds were estimated at 40.9 +/- 0.3 and 35.5 +/- 0.1 degrees C for O. albidipennis and O. laevigatus, respectively. The different optimum temperatures may explain, at least in part, the different distributions of the two species in the Palaeartic region and their population dynamics in greenhouses and natural vegetation in the south of Spain. The estimation of rm as a function of temperature showed high variability between years. Three release rates of 0.75-0.25 Orius per plant are recommended from early March to mid May to deal with thrips outbreaks in pepper crops.

Animals↗

PubMedDate not supplied

A long-term toxicity test comprising reproduction and growth of zebrafish with 4-chloroaniline.

This study describes a long-term test over three generations, using zebrafish (Brachydanio rerio) as the test species and concentrations of 1, 0.2, and 0.04 mg/L 4-chloroaniline (CA) as a model substance. The effect of the compound on the ecologically important parameters reproduction and growth was the focus of interest. Reduction in egg release by fish raised under CA was the most sensitive parameter in the test. Compared to the toxic threshold concentration for growth (0.4 mg/L), egg release was affected by a ten-fold lower concentration (0.04 mg/L). This study demonstrates that a long-term test is still the most appropriate method to assess the chronic toxicity of a substance on fish. A chronic toxicity test is proposed which comprises two generations, with the zebrafish as test species.

Aniline Compounds↗

PubMedDate not supplied

Reduced seminal parameters associated with environmental DDT exposure and p,p'-DDE concentrations in men in Chiapas, Mexico: a cross-sectional study.

In response to mounting concerns about the endocrine-disrupting influence of environmental chemicals on human health, this epidemiological study was initiated to test the hypothesis that nonoccupational exposure to the estrogenic pesticide 1,1,1-trichloro-2,2-bis(chlorodiphenyl)ethane (DDT) affects male reproductive parameters. One hundred and sixteen men aged 27 years (SD = 8.2) living in malaria endemic-areas in Chiapas (Mexico), where DDT was sprayed until 2000, participated in a cross-sectional study. Semen analyses were conducted according to World Health Organization methods and a quality control program was followed. DDT exposure was defined as the level of blood plasma p,p'-dichlorodiphenyl dichloroethylene (DDE), the major metabolite of DDT. The p,p'-DDE concentration adjusted for total lipids was 100 times higher than that reported for nonexposed populations at 45 plus or minus 32 mug/g (mean +/- SD). Crude regression analysis showed that several sperm motion parameters, including the percentage of motile sperm, decreased with higher p,p'-DDE concentrations (beta = -8.38; P = .05 for squared motility), and the percentage of sperm with morphological tail defects increased with higher plasma p,p'-DDE concentration (beta = 0.003; P = .017). Insufficient sperm chromatin condensation was observed in 46.6% of participants, and the most severe category of incomplete DNA condensation was also positively correlated with p,p'-DDE concentration (r = .223; P = .044). Therefore, nonoccupational exposure to DDT, as assessed by plasma p,p'-DDE concentrations, is associated with poorer semen parameters in men, indicating adverse effects on testicular function and/or the regulation of reproductive hormones. Previously, a causal role of environmental toxicants in human male infertility has been lacking because observed effects have been the result of unusually high exposures, either occupationally or as a result of industrial accidents, resulting in unprecedented controversy (reviewed by Cheek & McLachlan, Environmental hormones and the male reproductive system. J Androl. 1998;19:5). This is the first epidemiological study demonstrating effects after nonoccupational exposures to DDT. Based on these findings, the effect of DDT on male reproductive health should not be ignored.

Adolescent↗

PubMed1993

Developmental toxicity of gemcitabine, an antimetabolite oncolytic, administered during gestation to CD-1 mice.

Gemcitabine was given intravenously to female mice on gestation days (GD) 6-15 at doses of 0, 0.05, 0.25, or 1.5 mg/kg/day (0, 0.15, 0.75, or 4.5 mg/m2/day, respectively). Animals assigned to the teratology segment (25/group) were killed on GD 18 for examination of maternal hematologic parameters and organ weights, as well as fetal viability, weights, and morphology. The postnatal segment females (20/group) were allowed to deliver, and offspring physical, behavioral, and reproductive parameters were monitored. After offspring weaning, these dams were killed for hematologic and organ weight evaluations. At necropsy, 3 days after the final dose, the teratology segment dams showed dose-related increases in spleen and thymus weights. These changes were accompanied by a dose-related decrease in leukocytes and modest increases in mean corpuscular volume (MCV) and hemoglobin (MCH) at the two higher doses. On postpartum day (PPD) 21, the dams in the postnatal segment showed no treatment-related effects on these organ weights or hematologic parameters, indicating recovery of these maternal parameters within 3.5 weeks following termination of treatment. The decreases in maternal body weight and food consumption observed during gestation, and in liver and uterine weights at term in the 1.5 mg/kg/day group, were considered to be secondary to a high rate of prenatal mortality, evidenced by increased resorptions in the teratology segment and decreased live litter size in both segments of the study. Additional indications of developmental toxicity in this dose group were an increased incidence of malformations, primarily cleft palate, decreased fetal weights in the teratology segment, and decreased neonatal survival in the postnatal segment.(ABSTRACT TRUNCATED AT 250 WORDS)

Abnormalities, Drug-Induced↗

PubMed2002

Frequency of the antipsychotic therapy acute side effects in the treatment of acute psychosis.

Antipsychotic drugs produce a wide spectrum of physiological actions. Some of these effects differ among the various classes of antipsychotics. This medications have indications in the treatment of acute psychotic disorders. The main goal of this investigation was to determine the incidence and prevalence of the neuroleptic therapy acute side effects. The reason for this epidemiological investigation performing was the lack of knowledge of the exact neuroleptic therapy side effects incidence. Qualitative study on this problem has not been performed yet. Antipsychotic therapy side effects prevalence rate according to the literature data is ranging from 24% to 74%. Different prevalence rate is a consequence of different antipsychotic drug usage, different drug administration method and different side effects identification. On account of all these facts, we put the hypothesis on the correlation between the antipsychotic therapy and occurred side effects. Our experiment included all patients hospitalised from December 31st 1999 to January 31st 2000 in Intensive Care Unit of Biological Psychiatry Department of Psychiatric Clinic in Sarajevo. All patients were divided in three groups according to the applied therapy. All of them met ICD-10 criteria for schizophrenia (F20-29). During our study the following examinations were performed: psychiatric interview, BRPS, scale of side effects, psychophysiological tests, general clinical impression, scale of appetite, carbon hydrate needs scale. Psychiatric and statistical evaluations were done as well. The evaluation of our examination is showing successful results in all groups of patients. The improvement of psychopathological symptoms was insignificant. Reported side effects were minimal with low incidence rate and relatively high prevalence rate. Statistical tests were calculated from the obtained data after what the null hypothesis was rejected. Consequently, an alternative hypothesis was confirmed and it indicated that the acute side effects incidence and prevalence were within the range of expectation. Intensity of the recorded side effects was moderate to mild. On the basis of the obtained data, it has been concluded that applied antipsychotic agents did not induce more psychophysiological function impairments in the treated patients. Psychophysiological functions remained in physiological range limits and their changes were not significant. Neuroleptic therapy side effects were minimal, meaning no toxic signs or therapy discontinuations were recorded.

Journal Article↗

PubMed1984

Effects of weaning age on maternal reproduction and offspring health in rhesus monkeys (Macaca mulatta).

A study to systematically evaluate the effect of separation of mother and infant in the first year of life on maternal reproduction and long term offspring health was carried out. This study utilized outdoor harem breeding groups with an average ratio of one male to seven females. Female rhesus monkeys with live born infants (N = 750) were assigned to four weaning groups: 6, 8, 10, and 12 months. Two additional groups (N = 155) were included for comparison of reproductive parameters: females whose infants died at 90 days or less and females that had abortions or stillbirths. Females with infants weaned at 6 months had higher reproductive rates than other groups over the 18-month study period. Weaned infants were removed from the dam's cage and housed with age peers. No effect of weaning age was seen on overall measures of offspring health up to 2 years of age. Mortality and morbidity rates showed no differences between infant groups, although the proportion of trauma treatments increased with weaning age. Weights at 1 year varied with weaning group. These findings showed that infant age at separation from dam affected subsequent maternal reproduction without clinical detriment to infant health in harem groups of rhesus monkeys.

Age Factors↗

PubMedDate not supplied

Relationship between spontaneous behaviour at late pregnancy and reproductivity in mice.

The spontaneous behaviour at late pregnancy was measured as motor activity by Supermex in SHN mice, which have a rather high still-birth rate. The activities during both light and dark phases as well as during the total period were significantly higher in mice with still-birth than those with normal delivery. Meanwhile, in normal delivery group, there was little correlation between the spontaneous activity and the reproductive parameters, except for litter size or total pup weight. These results strongly suggest that calmness, especially at late pregnancy is prerequisite for normal delivery and that reproduction itself after delivery was not markedly affected by the behaviour of mother at late pregnancy.

Animals↗

PubMed1993

The association between antibody titres against Campylobacter fetus and reproductive efficiency in dairy cattle.

The relationship between the antibody titres against Campylobacter fetus and various indices of reproductive efficiency was studied in a cross-sectional study of 178 dairy cows from three California Dairy Herd Improvement Association herds. Blood samples were collected from the lactating cows during December 1986. Enzyme-linked immunosorbent assays were used to determine the antibody titres of the cow against Campylobacter fetus, Haemophilus somnus and Leptospira hardjo and were classified as either negative or positive. The status of a cow as either negative or positive against Campylobacter fetus and Haemophilus somnus represents serological evidence of natural exposure to the corresponding bacterial agents. However, the status against Leptospira hardjo was assumed to reflect a vaccinal titre since all the cows studied had been routinely vaccinated against this organism in September 1986. The data on demographic and reproductive parameters pertained only to the current lactation of the cows and were obtained from Dairy Herd Improvement Association individual cow records of December 1986. Five indices of reproductive efficiency were used, namely the recent calving interval, the calving-to-conception interval, the calving-to-last-service interval, the number of services per conception, and the number of services since last calving. The serological status against Haemophilus somnus, Leptospira hardjo and other covariates suggested by the results of previous studies were included in modelling the relationships of interest. Stepwise multiple linear regression analyses were carried out to study the adjusted relationship of Campylobacter fetus with each measure of reproductive efficiency. Multivariate analyses revealed that the adjusted relationship for Campylobacter fetus with all five measures of reproductive efficiency was non-significant (p > 0.05). Among the covariates, Leptospira hardjo had a strong and independent relationship with recent calving interval, the unstandardized partial regression coefficient being -0.77. The possible biological mechanisms of these associations are discussed.

Animals↗

PubMed1990

Photoperiod affects reproductive responsiveness to 6-methoxy-2-benzoxazolinone in house mice.

House mice (Mus musculus) have traditionally been characterized as nonphotoperiodic because reproductive function is unaffected by day length in the laboratory. In the present study, the reproductive responsiveness of CF1 mice to a naturally occurring plant metabolite was assessed in animals that were maintained in either long (16L:8D) or short (8L:16D) photoperiods from birth until the end of the study. Males and females were implanted i.p. with either an empty Silastic capsule or one containing 6-methoxy-2-benzoxazolinone (6-MBOA) at either 21 or 60 days of age for 3 days. Other 31-day-old mice were implanted with capsules for 8 wk. Three-day exposure to 6-MBOA stimulated uterine growth in short-day, adult females, but did not affect adult females housed in long photoperiods. Short-term treatment with 6-MBOA did not significantly affect reproductive parameters in either long- or short-day peripubertal house mice, or in adult males regardless of photoperiod, nor did exposure to 6-MBOA for 8 wk influence reproduction in males in either photoperiodic condition. However, short-day female mice had significantly reduced ovarian and uterine masses after 8 wk chronic 6-MBOA treatment as compared to long-day animals or mice unexposed to 6-MBOA. Short-day females exposed to 6-MBOA for 8 wk developed a denser pelage compared to long-day mice treated with this compound. Photoperiod-mediated differential responsiveness to 6-MBOA indicates that female house mice can discriminate long from short days, and these results suggest that the physiological mechanisms for photoperiodic responsiveness remain extant in this species previously characterized as nonphotperiodic.

Animals↗

PubMed2006

Impaired semen quality associated with environmental DDT exposure in young men living in a malaria area in the Limpopo Province, South Africa.

The pesticide DDT [1,1,1-trichloro-2,2-bis(chlorodiphenyl)ethane] is 1 of the 12 persistent organic pollutants (POPs) under negotiation at the Stockholm Convention to restrict or ban their production and use because of their toxicity, resistance to breakdown, bioaccumulation, and potential for being transported over long distances. DDT has estrogenic potential, and the main metabolite, p,p'-dichlorodiphenyl-dichloroethylene (p,p'-DDE), is a potent antiandrogen. In response to mounting evidence on the endocrine-disrupting influence of environmental chemicals on human health, this epidemiological study was initiated to test the hypothesis that nonoccupational exposure to DDT affects male reproductive parameters. In a cross-sectional study, healthy male subjects (n=311) between 18 and 40 years (23+/-5) of age were recruited from 3 communities in an endemic malaria area in which DDT is sprayed annually. A semen analysis according to World Health Organization (WHO) standards was performed. The Hamilton Thorne Computer Assisted Sperm Analysis (CASA) system was simultaneously used to determine additional sperm motility parameters. Blood plasma samples were assayed for p,p'-DDT and metabolites as a measure of exposure. The exposure levels were expressed as lipid-adjusted p,p'-DDT and p,p'-DDE values. The mean p,p'-DDT and p,p'-DDE concentrations were 90.23 microg/g(+/-102.4) and 215.47 microg/g(+/-210.6), respectively. The multivariate linear regression analyses indicated that mean CASA motility was lower with a higher p,p'-DDE concentration (beta=-0.02, P=.001) and the CASA parameter beat cross-frequency (BCF) was higher with a higher p,p'-DDT concentration (beta=0.01, P=.000). There was also a statistically significant positive association between percent sperm with cytoplasmic droplets and p,p'-DDT concentration (beta=0.0014, P=.014). The ejaculate volume (mean 1.9+/-1.33 mL) was lower than the normal range (>or=2.0 mL) according to WHO, and a significant decrease with increasing p,p'-DDE values was seen for both square root-transformed volume (beta=-0.0003; P=.024) and count (beta=-0.003; P=.04). Although there were no associations between either p,p'-DDT or p,p'-DDE concentrations and the rest of the seminal parameters, the incidence of teratozoospermia (99%; normal sperm<15%) was high. Twenty-eight percent of the study group presented with oligozoospermia (<20x10(6) sperm/mL), which had a significant positive association with p,p'-DDE (odds ratio [OR]=1.001, P=.03). There was a significant positive association between participants with asthenozoospermia (32%) and p,p'-DDT (OR 1.003, P=.006) and p,p'-DDE (OR 1.001, P=.02). The results imply that nonoccupational exposure to DDT is associated with impaired seminal parameters in men. The high exposure levels of p,p'-DDT and p,p'-DDE are of concern because these levels could have far-reaching implications for reproductive and general health.

Adult↗

PubMed1997

[The effect of different high riboflavin supplements during pregnancy and lactation on performance and erythrocyte glutathione reductase activity of rats].

In two experiments with 160 female Sprague-Dawley rats the influence of various dietary riboflavin supplementations during lactation and during pregnancy and lactation were examined on food intake, body mass, reproduction, hematologic profile and the erythrocyte glutathione reductase activity coefficient (EGR-AC). In the first trial rats were fed a semisynthetic, riboflavin-deficient diet, based on casein and corn starch with various riboflavin supplementations during lactation (0, 2, 4, 6, 8, 10, 12, 40, 400, 4000 mg riboflavin/kg diet). In the second experiment the rats received supplements of 1 and 20 mg riboflavin/kg diet, respectively, during pregnancy. After parturition each group was divided into three sub-groups with riboflavin supplementations during lactation of 1, 5 and 20 mg/kg diet, respectively. Both investigations ended at the 14th day of lactation. Food intake was decreased significantly by 25% and 11% in the groups without riboflavin supplementation or 1 mg riboflavin/kg diet. In the same groups body mass was reduced by 11% and 4%, respectively. With regard to the reproduction parameters the riboflavin supply influenced only the litter mass at the 14th day of lactation and only lactational supply was relevant. In both trials the results of the hematologic profile showed no differences. In riboflavin deficiency (0 or 1 mg riboflavin/kg diet, respectively) the EGR-AC was increased significantly to 1.9 and 1.8, respectively. At the supplementation of 4-5 mg riboflavin/kg diet EGR-AC reached a plateau of 1.45, which was not improved by higher supplements. Concerning the whole reproduction cycle (trial II) there was a stronger influence of the actual lactation-supply on EGR-AC, on the other hand a riboflavin deficiency in pregnancy could be compensated only partially by an optimal supply in lactation. Therefore, based on the parameter EGR-AC an optimal riboflavin supply is recommended for each part of the reproduction cycle. By means of EGR-AC also the riboflavin requirement for lactating rats was derived. Feeding a semisynthetic diet (17.4 MJ ME/kg DM, 20.8% crude protein in DM) a supplementation of 5-6 mg riboflavin/kg or a total content of 6-7 mg/kg diet is recommended.

Animals↗

PubMed1987

Experimental studies on reproduction with the lipid-regulating agent gemfibrozil.

Gemfibrozil, a new lipid-regulating agent, was evaluated in rats and rabbits for effects on various phases of the reproduction process. In teratology studies groups of pregnant rats and rabbits received gemfibrozil at doses up to 200 mg/kg during organogenesis (rat, Days 6-15; rabbit, days 6-18). For peri- and postnatal studies, groups of pregnant rats were given 92 or 331 mg/kg from Day 15 of gestation through weaning. In fertility studies groups of sexually mature male rats were given 93 or 326 mg/kg of gemfibrozil for 61 days and females were given 94 or 318 mg/kg for 15 days prior to mating within treatment groups. Drug administration continued in females through gestation and weaning of the F1 offspring. In subsequent fertility experiments, treated male rats were mated with untreated females and treated females were cohabitated with untreated males. Gemfibrozil did not elicit a teratogenic response in either rats or rabbits up to doses that resulted in maternal toxicity. Reduced pup weights during the neonatal and weaning periods in the female fertility study as well as in the perinatal-postnatal study were the only apparent drug effect. Treatment of female rats prior to mating had no significant effects on general reproductive parameters. Male rats given doses of about 300 mg/kg/day showed inconsistent and equivocal lower rates of fertility relative to the concurrent controls. No adverse effects were seen in the reproductive performance of offspring of gemfibrozil-treated male rats.

Animals↗

PubMed2005

Comparative study on biological parameters of Bemisia tabaci (Genn.) collected on four host plants from Varamin-Iran.

During 2003 biological parameters of sweetpotato whitefly, B. tabaci (Genn.) (Horn. Aleyrodidae) as a major pest of field crops, vegetables and ornamentals were studied. In this study, the infested leaves of cucumber (Cucumis sativus L.) zucchini (Cucurbita pepo L.) eggplant (Solanum melongena L.) and cotton (Gossypium hirsutum L.) with whitefly nymphs and pupae were collected from Varamin-Iran, and were transferred to the laboratory. The newly emerged males and females of each population were released separately into a large cage set on cotton plants. Experiments were carried out in a growth chamber on cotton, (Varamin 76 variety) at 24+/-2 degrees C, 55+/-3% RH and 16:8 h (L: D) photoperiod. The adults of every collected population after emergency were reared in the large cages (40 x 50 x 70) containing pots of cotton plant. The preimaginal developmental time and reproductive parameters of 40 mated females were calculated for each population. The results revealed that the intrinsic rates of increase (r(m)), on cucumber, zucchini, eggplant and cotton were 0.093, 0.068, 0.085 and 0.078 respectively, gross fertility rate, were 67.92, 59.08, 76.13 and 63.14 respectively and mean generation time (T(c)) were 27.4, 27.74, 27.73 and 27.52 days respectively. Other demographic parameters such as intrinsic birth rate (b), intrinsic death rate (d), finite rate of increase (lambda), doubling time (DT), net fecundity rate, net fertility rate , gross fecundity rate, mean age gross fecundity and fertility, mean age net fecundity and fertility, mean age hatch, number of eggs/female/day and daily reproductive rate were also calculated. The results revealed that there were not significant differences between parameters of demography in different populations and the host plant has no significant influence on biological parameters.

Animals↗

PubMed1980

Effect of male to female ratios on reproduction of caged coturnix D1 breeders.

Two separate trials were conduced with Coturnix quail (D1 strain) to determine the effect of sex ratios on reproductive efficiency over five 28-day periods. Periods 1 to 3, 1 to 4, and 1 to 5 were analyzed for treatments which housed one male with either one, two, or three females to determine which ratio was the most efficient for a given period of time and for continued efficiency throughout the period analyzed. Results indicated that increasing the sex ratio up to one male to three females per cage had no significant detrimental effect on reproductive parameters and resulted in greater overall efficiency.

Animals↗

PubMedDate not supplied

Comparison of cellular and whole-animal bioassays for estimation of radiation effects in the polychaete worm Neanthes arenaceodentata (Polychaeta).

The polychaete worm Neanthes arenaceodentata was used in experiments to determine possible relationships between short-term genotoxicity tests and reproductive and lethal consequences of exposure to ionizing radiation. Groups of juvenile N. arenaceodentata received one of four different radiation doses (2, 4, 8, and 16 Gy) to determine dose-effect estimates for chromosomal aberration induction, and groups of both adult and juveniles received one of seven different radiation doses (1, 4, 8.4, 46, 102, 500, and 1000 Gy) to determine dose-effect estimates for reproduction, mortality, and life span. Effects on reproduction and genetic material were observed at the lowest doses and in the same range; detrimental reproductive effects were observed at 1 to 4 Gy, and the frequency of chromosomal aberrations was significantly increased at 2 Gy. Only high doses resulted in acute mortality (greater than 500 Gy) and decreased life span (greater than 100 Gy). Dose-effect estimates for chromosomal aberration induction were dependent on radiation dose and on the stage of the cell cycle at the time of irradiation. Dose-effect estimates for reproduction were dependent on dose and the potential for repopulation of gonadal tissue. It is concluded that short-term genotoxicity test can be predictive of detrimental reproductive effects in those model systems for which basic cell kinetics and reproductive parameters are well known.

Animals↗

PubMed2002

Reproductive medicine of companion marsupials.

Marsupials have recently become popular as exotic pets. Marsupial reproduction is considerably different than that of placental mammals. The reproductive parameters and artificial milk formulations specific for marsupials are discussed.

Animals↗