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PubMed2005

The association of partner abuse with risky sexual behaviors among women and men with HIV/AIDS.

Prior studies have found that partner abuse is related to risky sexual behavior. However, few studies have explored gender, sexual orientation, or substance use differences in this association, especially among people with HIV. We examined data from the Risk and Prevention survey from the HIV Cost and Services Utilization Study (HCSUS) sample on 726 sexually-active individuals in three gender/orientation groups (286 women, 148 heterosexual men, and 292 gay/bisexual men). The study assessed whether individuals with HIV who experienced or perpetrated abuse within a close relationship were likely to engage in unprotected intercourse with that same partner. Both abuse perpetration and victimization were significantly associated with having any unprotected intercourse. In multivariate tests, gender/orientation and substance use during sex moderated the perpetration effects. Secondary HIV prevention interventions need to take into account potentially abusive contexts in which sexual activity may occur for both men and women.

Adult↗
PubMed1989

Changes in forebrain Na,K-ATPase activity and serum hormone levels during sexual behavior in male rats.

We have previously shown that Na,K-ATPase activity (the enzymatic machinery for the sodium pump) in brain areas such as the medial basal hypothalamus (MBH) and the preoptic-suprachiasmatic region (POSC) can be changed by experimental manipulations of gonadal function. We now report enzyme levels in brain regions as related to hormonal changes occurring during sexual behavior. Male rats were exposed to receptive females and decapitated immediately after displaying one of the following behavioral events: the start of copulatory activity, first ejaculation, and the beginning of a second copulatory series. A group of noncopulating animals were used as control. The variables measured included serum levels of LH, PRL and testosterone and Na,K-ATPase activity in MBH, POSC and parietal cerebral cortex (CC). A steady increase in enzyme activity in the POSC, but not the MBH or CC, was found in copulating animals. Serum LH levels changed in a similar fashion. A sharp increase in serum PRL levels, seemingly related to ejaculation, was also observed. These data are consistent with our previous findings on monoaminergic neurotransmission in brain regions related to male sexual behavior.

Animals↗
PubMed2004

Ethnic variation in drinking, drug use, and sexual behavior among adolescents in Hawaii.

This study examined ethnic differences in substance use and sexual behavior and whether drinking and drug use constitute risk factors for unsafe sexual practices among Native Hawaiian (NH), Caucasian, and Asian/Pacific Islander (API) high school students in Hawaii. A secondary data analysis of the Youth Risk Behavior Survey (1997 and 1999) using a representative sample of 2,657 students in 9-12 grades was performed. Chi-square tests for bivariate associations and multivariate regression analyses were conducted to identify predictors. NHs were more sexually active, initiated sex earlier, and tended to have multiple partners. Alcohol lifetime use was higher in NH, Caucasians, and males. NHs were more likely to initiate drinking by age 12 and engage more in episodic drinking. Non-episodic or episodic drinkers and students who use drugs were at risk to engage in sexual activity, have multiple partners, and use alcohol/drugs during sex. Risk was two times higher for substance use during sex if drinking was initiated at age 10 or younger compared to 15 years or older. Compared to abstainers, the risk doubled for lifetime multiple partners if drinking was initiated at ages 13-14. Overall, females were more sexually active. Because drinking was associated with sexual initiation and risky behavior, adverse effects of alcohol must be addressed in programs targeting underage drinking, thus helping youth delay or minimize sexual activity and prevent other associated problems. Intervention efforts should enhance life skills that endorse abstinence from alcohol and drug use.

Adolescent↗
PubMed1998

Factors influencing ovarian activity and sexual behavior of postpartum mares under farm conditions.

Management of the postpartum period is one of the most important factors of stud farm medicine. In horses, owing to the long gestation period, the time from parturition to repeat conception needs be short to maintain an optimal yearly foaling interval. For this reason the features of postpartum ovarian activity and sexual behavior were studied under farm conditions. During 2 consecutive breeding seasons, 107 mares on 5 commercial horse farms were monitored after parturition by regular teasing, transrectal ultrasonography and blood sampling for progesterone. Foalings took place from January 1 to June 15. Body condition scoring was carried out within 5 d and at 60 to 65 d after parturition. The first ovulation occurred within 20 d after foaling in 84.1% (90/107) of the mares. The mean intervals from foaling to the first and second ovulations were 17.8 +/- 1.6 d (+/- SEM) and 40.9 +/- 2.7 d (+/- SEM), respectively. The mean intervals from parturition to the first and second ovulation (P < 0.001), the interovulatory interval (P < 0.01), the second follicular phase (P < 0.001), and the time until the first overt estrus (P < 0.01) were significantly longer in mares foaling before the vernal equinox. In the beginning of the breeding season the intervals from parturition to the first ovulation (P < 0.01), to the second ovulation (P < 0.01), and to the first overt estrus (P < 0.001) were significantly longer for primiparous mares than for multiparous animals. There was a tendency for an increased interovulatory interval and for a longer second follicular phase in mares with decreased body condition after parturition (P = 0.069, P = 0.089, respectively). Suckling and breed had no effect on postpartum ovarian activity. We concluded that under field conditions the resumption of cyclic ovarian activity and sexual behavior in mares after foaling are strongly affected by the season of parturition and parity. In some cases, body condition change and other factors may also play a role in influencing postpartum reproductive function.

Animals↗
PubMed1982

Effects of testosterone, dihydrotestosterone, or estradiol administered neonatally on sexual behavior of female ferrets.

Groups of female ferrets born in the laboratory received sc Silastic capsules containing testosterone (T), 5 alpha-dihydrotestosterone (DHT), 17 beta-estradiol (E), or no steroid for 15 days beginning on the day of birth; an additional group of male ferrets received empty sc capsules neonatally. All ferrets were gonadectomized at 11 weeks of age and were subsequently tested for masculine and feminine sexual behaviors while being treated consecutively over an 8-month period with several different gonadal steroids. The ability to display masculine sexual behavior was studied in the absence of replacement hormones and during a counterbalanced sequence of treatments with Silastic capsules containing T, E, or DHT. The maximal amount of neck grip, mount, and pelvic thrusting behavior displayed, regardless of adult endocrine treatment, was significantly greater in control male and neonatally T-treated females than in females that had received no hormone, E, or DHT neonatally. Animals in all five groups displayed equivalent increments in sexual receptivity in response to daily sc injections of increasing dosages of estradiol benzoate. Polyacrylamide gel electrophoresis of plasma collected from newborn female ferrets revealed no binding of either [3H]E or [3H]T, whereas two binding peaks were found for [3H]DHT. After the administration of androgen in adulthood, equivalent clitoral growth and ossification occurred in females given either T or DHT neonatally. These results suggest that in ferrets, behavioral masculinization occurs in response to neonatal exposure to T itself and not to its major neural metabolites, E and DHT. They also show that behavioral defeminization fails to occur in ferrets even after neonatal exposure to pharmacological amounts of E, T, or DHT.

Animals↗
PubMed2004

In the ventral tegmental area picrotoxin blocks FGIN 1-27-induced increases in sexual behavior of rats and hamsters.

RATIONALE AND OBJECTIVES: There are two types of benzodiazepine receptors, mitochondrial benzodiazepine receptors (MBRs), and gamma-aminobutyric acid (GABA(A))/benzodiazepine receptor complexes (GBRs). MBR activation increases neurosteroidogenesis. Ventral tegmental area (VTA) infusions of the MBR agonist, FGIN 1-27, increase midbrain levels of the progesterone metabolite 5alpha-pregnan-3alpha-ol-20-one (3alpha,5alpha-THP) and lordosis of rats and hamsters. Activation of GBRs leads to membrane hyperpolarization. In the VTA, infusions of GBR agonists enhance 3alpha,5alpha-THP-facilitated lordosis. Thus, if, in the VTA, MBR-mediated increases in 3alpha,5alpha-THP enhance sexual responses via actions at GBRs, then blocking GBRs with picrotoxin will reduce FGIN 1-27-induced increases in sexual behavior of female rodents. METHODS: Ovariectomized rats and hamsters, with unilateral guide cannula to the VTA, received estradiol benzoate (10 mug; EB) at hour 0. Hamsters also received progesterone (100 mug) at hour 44. At hour 47.5, all animals were infused first with 10 ng or 20 ng picrotoxin or saline, vehicle to the VTA and, 30 min later, with 5 mug/11.4 nM FGIN 1-27 or saline, vehicle. Ten minutes later, animals were tested for sex and motor behavior. RESULTS: Picrotoxin, but not vehicle, infusions blocked FGIN 1-27-mediated increases in lordosis of rats and hamsters, proceptivity of rats, and sexual responsiveness of hamsters. In addition, midbrain 3alpha,5alpha-THP levels were higher in animals that received VTA infusions of FGIN 1-27, compared to those infused with saline, vehicle. CONCLUSION: In the VTA, GBRs are required for MBR-enhanced sexual behavior of EB-primed rats and EB- and progesterone-primed hamsters.

Animals↗
PubMed1980

Vomeronasal pump: significance for male hamster sexual behavior.

Vomeronasal chemoreceptors segregated within the vomeronasal organ are important for male hamster sexual behavior. An autonomically controlled vascular pump, previously demonstrated in anesthetized animals, can transport stimuli to the receptors. Interruption of the efferent nerves controlling the pump results in behavioral deficits similar to those produced by interruption of the afferent nerves carrying information from the vomeronasal organ to the brain. Pump activation is thus a prerequisite for normal vomeronasal stimulation in behaving animals.

Animals↗
PubMed1978

Monoamines, estrogen and female sexual behavior in the golden hamster.

In the golden hamster drugs which inhibit monoaminergic function (including p-chlorophenylalanine (PCPA), methysergide and a-methyl-p-tyrosine (a-MPT) facilitated lordosis in ovariectomized female hamsters as a function of the duration of estradiol benzoate (EB) priming. a-MPT (200 mg/kg), methysergide (6 mg/animal) or PCPA (150 or 360 mg/kg) potentiated lordosis if 6 days of EB priming preceded drug treatment. However, if female hamsters were primed with EB for only 2 days, a-MPT and methysergide were ineffective. PCPA (360 mg/kg) was less effective after 2 days of EB than after 6 days of EB priming. alpha-MPT produced a three-fold elevation in progesterone levels in ovariectomized females but methysergide and PCPA did not influence serum progesterone. PCPA (360 mg/kg) facilitated lordosis in adrenalectomized, ovariectomized females, eliminating the possibility that adrenal progesterone is essential for the behavioral effects of the drug. Luteinizing hormone-releasing hormone levels in the preoptic/anterior hypothalamic area and the medial basal hypothalamus were also not significantly altered at 1 h after PCPA injection. Pimozide (1.5 mg/kg) and pimozide (1.5 mg/kg) and amphetamine (2.5 mg/kg) did not potentiate lordosis in ovariectomized hamsters after either 2 or 6 days of EB priming. Pargyline, a monoamine oxidase inhibitor, inhibited female sexual behavior in females in estrogen alone-induced estrus. Lordosis in the female rat is more readily elicited both by drugs and estrogen. It is proposed with regard to female sexual behavior that species differences in estrogen sensitivity may underlie apparent differences in drug sensitivity.

Adrenalectomy↗
PubMed2005

Impaired female sexual behavior of rat offspring exposed to Solanum lycocarpum unripe fruits during gestation and lactation: lack of hormonal and fertility alterations.

Solanum lycocarpum St. Hil (Solanaceae) is an invasive and native shrub very common in the Brazilian savanna. It is well known that this plant contain steroidal glycoalkaloids that can be transformed into an intermediate for steroidal drugs production, like oral contraceptives. In this way, it is very possible that these glycoalkaloids and its aglycone, once in the body by ingestion of S. lycocarpum fruits, may act disrupting to the endocrine system. Rat offspring were exposed to S. lycocarpum unripe fruits (10% in the diet) from gestational day (GD) 06 to post-natal day (PND) 07. The female exposed offspring showed, at adult age (PND 100), impaired sexual behavior. However, the fecal hormonal metabolite levels, measured at PND 30, PND 60 and PND 90, and the fertility (PND 120) of male and female experimental offspring were normal. We can assume that the steroidal glycoalkaloids, solamargine and solasodine, present in the fruit, are degradated, once inside the organism, to the steroidal alkaloid solasodine, which may penetrate, by simple diffusion, the placental and/or the hematoencephalical barriers and impact the fetuses. Finally, S. lycocarpum fruit may act as phytohormones, promoting perhaps some neural alterations that at adult age may impair the sexual behavior of the experimental female without impairing the fertility and sexual hormone synthesis. These changes observed can be the direct consequence of the toxic actions of the steroidal alkaloid on the female offspring during fetal development.

Analysis of Variance↗
PubMed2001

The synaptic organization of VMH neurons that mediate the effects of estrogen on sexual behavior.

Estrogen acts in the hypothalamic ventromedial nucleus (VMH) of female rats to promote sexual behavior, as typified by the lordosis response. Morphological changes in the VMH, such as increased synaptic profiles and increased dendritic spines, suggest that estrogen may modulate behavior by altering VMH synaptic organization. To understand the significance of these changes, this laboratory has been investigating the functional classes of lordosis-relevant neurons and their local connectivity. A neurotropic virus, pseudorabies virus (PRV), was used to transneuronally label the CNS network that controls the lordosis-producing muscles. When PRV was placed in the lumbar epaxial muscles, it was sequentially detected in the lumbar ventral horn, the medullary reticular formation, the periaqueductal gray, and finally the VMH. Subsequent analysis showed that the population of VMH neurons that were initially infected with PRV largely resided beyond the cluster of estrogen receptor-containing neurons. In a separate study, VMH neurons were visualized with Lucifer yellow, and their morphology was analyzed using confocal microscopy. Such analysis confirmed that estrogen treatment increased dendritic spines in the VMH. The particular VMH neurons in this study did not express nuclear estrogen receptor, which suggests that estrogen can increase spine density indirectly. These results represent initial steps toward unraveling the local circuit that mediates estrogenic action on a specific reproductive behavior.

Animals↗
PubMed1995

Postweaning housing conditions and partner preference and sexual behavior of neonatally ATD-treated male rats.

Male rats were neonatally treated with cholesterol or a substance that blocks the aromatization of testosterone to estradiol (1,4,6-androstatriene-3,17-dione: ATD). At weaning (21 days) they were either housed alone or in small groups (2-3 animals) and tested for partner preference behavior (PPB) in adulthood. Choice was between an estrous female and an active male (Part I) and between an estrous female and an ATD-male (Part II). Tests were carried out in a 3-compartment box. Social isolation did not have major effects on PPB except when sexual interaction with the stimulus animals was prevented (Part I). In this case, isolates (ATD and control) showed higher preference scores (PS) for the estrous female and spent less time in the empty middle compartment. When the choice was between an estrous female and an ATD-male, partner PS decreased in all males, most clearly in ATD-males. The latter animals spent more time with the stimulus ATD-male than they had done in previous PPB tests with the normal stimulus male. In contrast to partner preference behaviors, sexual behavior was clearly affected by social isolation. Isolates (ATD and control) displayed lower frequencies of mounts and intromissions. These effects persisted over consecutive tests. Ejaculation was not affected. In conclusion, the present results confirm earlier findings about the significance of neonatal endocrine conditions for the organization of adult PPB in male rats. The presence or absence of social conspecifics after weaning appears to have little influence on adult PPB.

Androstatrienes↗
PubMed1994

Hypothalamic monoamine oxidase activity in ovariectomized rats after sexual behavior restoration.

The effect of estradiol benzoate, progesterone and a sequential treatment with both on the activity of the enzyme monoamine-oxidase (MAO) was assessed in mitochondria from hypothalami of ovariectomized rats. A differential effect on the subtypes A and B MAO was found according to the type of treatment. Estradiol benzoate administration decreased MAO activity, mainly that of MAO-A. Progesterone alone had no effect, and sequential treatment with estradiol benzoate plus progesterone restored sexual behavior and produced a significant increase of MAO-A activity, without changes in total MAO activity. Since MAO-A is an isoform of MAO that preferentially uses norepinephrine and serotonin as substrates and MAO-B acts on phenylethylamine and benzylamine as substrates, our findings suggest that the restoration of sexual behavior after the treatment with estradiol benzoate followed by progesterone may be associated with the differential effect exerted by the hormones on MAO subtypes, rather than to the simple decrease in hypothalamic monoamine concentrations as reported in the literature.

Animals↗
PubMedDate not supplied

Changes at a human immunodeficiency virus testing clinic in the prevalence of unsafe sexual behavior among men who have sex with men.

GOAL: Given reductions in risky sexual behavior reportedly occurring during the 1980s among men who have sex with men, the authors sought to assess if such trends are continuing. STUDY DESIGN: The authors analyzed initial visit data for 4,880 men who presented at a human immunodeficiency virus testing clinic from 1988 through 1993 and who reported any male partners during the preceding 12 months. RESULTS: From 1988 to 1993, the percent of men who have sex with men reporting any oral sex (virtually all of which was unprotected) or any anal sex (more than two-thirds of which was unprotected) during the previous 6 months increased from 78% to 90% (P < 0.001) and from 47% to 55% (P = 0.6), respectively. Adjusting for demographics and numbers of partners did not change results. CONCLUSIONS: Unprotected anal sex persists, whereas unprotected oral sex is increasing among men who have sex with men and who present for human immunodeficiency virus testing. New strategies are needed to reduce human immunodeficiency virus risk among men who have sex with men.

Adult↗
PubMed1990

Sexual behavior, venereal diseases, hygiene practices, and invasive cervical cancer in a high-risk population.

A case-control study of 759 women with invasive cervical cancer and 1430 controls in four Latin American countries evaluated risk in relation to sexual behavior, histories of specific venereal diseases, and hygiene practices. Early age at first sexual intercourse and increasing number of sexual partners were associated with significantly increased risks even after adjustment for their mutual effects. Risk increased to a twofold excess among women reporting first intercourse at 14 to 15 years of age compared with 20+ years. The number of steady sexual partners was a more important predictor of risk than the number of nonsteady partners, particularly before age 30, possibly reflecting the need for prolonged or repeated exposures to a transmissible agent, or different methods of protection against sexually transmitted diseases or pregnancy. Reported frequency of intercourse was not generally associated with risk, except among women reporting increased frequencies before 20 years of age. Histories of gonorrhea or crab lice were associated with increased risk, but histories of other venereal diseases were not significant predictors. No consistently increased risks were detected for women reporting specific hygiene or douching habits, except the practice of washing the genitalia infrequently during menstruation. These results provide support for a period of increased susceptibility to carcinogens during adolescence, and suggest that this may be an important determinant of the high incidence of cervical cancer in Latin America.

Adolescent↗
PubMed2004

Social, cultural and sexual behavioral determinants of observed decline in HIV infection trends: lessons from the Kagera Region, Tanzania.

This paper is a follow-up of earlier findings by the Kagera AIDS Research Project (KARP), which documented declining trends in the prevalence and incidence of HIV infection in the Kagera region of Tanzania. The paper examines socio-cultural and sexual behavioral changes as possible determinants of the observed declining trends in Bukoba, the largest urban area of the region. The study used in-depth interviews, focus group discussions, field observations and ethnographic assessments to collect the required data. The findings suggest that since the initial years of the epidemic there have been significant changes in sexual behaviors, norms, values, and customs that are considered high-risk for HIV transmission. The findings show an increase in condom use, abstinence, zero grazing (sticking to one sexual partner) and uptake of voluntary HIV testing while traditional practices such as polygamy, widow inheritance, excessive alcohol consumption, and sexual networking are declining. We suggest that these changes are partly a result of the severity of the epidemic itself in the study area, and interventions that have been carried out in this area since 1987. The major interventions have included health education, the distribution of condoms, AIDS education in schools, voluntary HIV counseling and testing. These are encouraging findings that give hope and we believe that other places within Tanzania and other countries experiencing a severe AIDS crisis have much to learn from this experience. However, changes in norms and behavior are vulnerable; people in Kagera are still at risk and there is a need for continued intervention together with monitoring of the direction of the epidemic.

Adolescent↗