The effect of anabolic-androgenic steroids on sexual behavior and reproductive tissues in male rats

Nonobstructive azoospermia: an etiologic review

ABSTRACT

Azoospermia is the complete absence of spermatozoa in the ejaculate in two or more semen analyses after centrifugation. Nonobstructive azoospermia (NOA) represents the most severe form of male factor infertility accounting for 10%-15% of cases and stems from an impairment to spermatogenesis. Understanding of the hypothalamic-pituitary-testicular axis has allowed NOA to be subcategorized by anatomic and/or pathophysiologic level. The etiologies of NOA, and therefore, the differential diagnoses when considering NOA as a cause of male factor infertility, can be subcategorized and condensed into several distinct classifications. Etiologies of NOA include primary hypogonadism, secondary hypogonadism, defects in androgen synthesis and/or response, defective spermatogenesis and sperm maturation, or a mixed picture thereof. This review includes up-to-date clinical, diagnostic, cellular, and histologic features pertaining to the multitude of NOA etiologies. This in turn will provide a framework by which physicians practicing infertility can augment their clinical decision-making, patient counseling, thereby improving upon the management of men with NOA.

Immediate and late effects of supraphysiological doses of nandrolone decanoate on the testis of rats

PURPOSE

To investigate the effects of supraphysiologic doses of nandrolone decanoate on the testicular morphology of rats and if these effects could be transitory or permanent.

METHODS

Twenty-five male rats were divided in four groups. C28 and C40 were control rats killed with 28 and 40 weeks old, respectively; and T28 and T40 were treated with nandrolone decanoate (10 mg/kg) and killed immediately after the treatment (T28) or 12 weeks after the end of treatment (T40). The testis weight and volume were measured, and the seminiferous tubule area and epithelium height were assessed by histomorphometric methods.

RESULTS

The seminiferous tubules area and epithelium height of group T28 were reduced in comparison to C28. Group T40 showed reduced testicular weight and volume, as well as seminiferous tubule area and epithelium height in comparison to C40.

CONCLUSION

The use of nandrolone decanoate promotes major structural modifications on the testes of rats. These modifications are even worse 12 weeks after ending the use of the anabolic androgenic steroid.

Nandrolone decanoate induced kidney injury through miRNA-146a targeting IRAK1 and TRAF6 via activation of the NF-κB pathway: The effect of moderate exercise

Anabolic-androgenic steroids (AAS) abuse is linked to some abnormalities in several tissues including the kidney. However, the precise molecular mediators involved in AAS-induced kidney disorder remain elusive. The main objective of the present study was to investigate the effect of Nandrolone decanoate on kidney injury alone or in combination with moderate exercise and its related mechanisms. Thirty-two male Wistar rats were subdivided randomly into four groups. control (Con), Nandrolone (10 mg/kg)(N), Exercise (Exe), Nandrolone + Exercise (N+Exe). RESULTS: After 6 weeks, nandrolone treatment led to a significant increase in functional parameters such as serum cystatin c, urea, creatinine, albuminuria and Albumin/ creatinine ratio indicating kidney dysfunction. Moreover, nandrolone treatment increased vacuolization, focal inflammation, hemorragia, cast formation fibrosis in the renal tissue of rats. miRNA-146a increased in kidney tissue after nandrolone exposure by using RT-PCR which may be considered idealtheranomiRNAcandidates for diagnosis and treatment. Western blotting indicated that IRAK1, TRAF6, TNF-α, NF-κB, iNOS and TGF-β protein expressions were considerably elevated in the kidneys of nandrolone treated rats. Moderate exercise could alleviate the renal dysfunction, histological abnormalities and aforementioned proteins. Our findings suggested that nandrolone consumption can cause damage to kidney tissue probably through miRNA-146a targeting IRAK1 and TRAF6 via activation of the NF-κB and TGF-β pathway. These results provide future lines of research in the identification of theranoMiRNAs related to nandrolone treatment, which can be ameliorated by moderate exercise.

Abuse of Anabolic-Androgenic Steroids as a Social Phenomenon and Medical Problem-Its Potential Negative Impact on Reproductive Health Based on 50 Years of Case Report Analysis

Background/Objectives: Illegal anabolic-androgenic steroids are a significant lifestyle factor in infertility. The aim of our study was to analyze clinical cases resulting from their use for their frequency, geographical location, dynamics, substances used, the age and gender of the users, and the types of clinical complications. Methods: Publications were obtained by searching PubMed for the following terms: 'anabolic-androgenic steroids' and 'clinical case'. Publications from 1973 to 2022 were qualified for the analysis. Results: An increasing trend in the number of clinical cases resulting from the use of steroids, as well as the number of substances used simultaneously, was observed. The substances changed over the decades, but in the last 20 years, testosterone, nandrolone, stanozolol, methandienone, trenbolone, and methenolone have predominated. Cardiological side effects predominated in each period, with a continuous increase in their occurrence. The most common among these were myocardial infarctions and hypertrophic cardiomyopathy. The next most numerous adverse events involved psychiatric, endocrinological, hepatic, and oncological problems. We demonstrated a possible relationship between the use of individual steroids and medical issues; the strongest associations were between testosterone and endocrine complications, and methylstenbolone and hepatic complications. Conclusions: There has been an increasing trend in case reports describing serious health problems associated with the use of anabolic-androgenic steroids, a tendency to use several substances simultaneously, and a preferential use of substances with a high potential of causing serious side effects. These phenomena mainly concern men, with an average age of 30, and the health problems that dominate in clinical case reports-including serious cardiological, psychiatric, endocrinological, hepatic, and oncological diseases-may potentially affect reproductive health and pose a challenge for reproductive medicine.

Illegal Use of Testosterone and Other Anabolic-Androgenic Steroids in the Population of Amateur Athletes in Wrocław, Poland-An Unfavorable Lifestyle Trend in the Population of Men of Reproductive Age

Background: One factor that may negatively impact male reproductive health is the illegal use of testosterone and anabolic-androgenic steroids. This study aimed to evaluate the prevalence of testosterone use in recreational athletes, as well as factors associated with its use, and to determine the profile of a person using testosterone. Methods: A cross-sectional analysis of data from an anonymous, online questionnaire of men recruited from gyms, randomly selected in Wrocław, Poland, has been performed. The minimal sample size was evaluated with the univariate logistic regression model. The association between testosterone use and other factors was also evaluated with the univariate logistic regression model. Results: A total of 35% of respondents used testosterone. The main purposes of testosterone use were the improvement of training effects and the improvement of body shape. The respondents most likely to use testosterone and other anabolic-androgenic steroids were men aged 26-35, whose earnings were at the level of the middle class or higher, who were married, had children, had training experience of at least 6 months, exercised at least once a week, took part in weightlifting competitions, were managers in a corporation or enterprise, or were self-employed. Most of the people using testosterone had self-treated side effects. Conclusions: The profile of the person most likely to use testosterone corresponds to the characteristics of men in optimal socio-demographic conditions for reproduction. These results indicate that this is a significant social problem that may impact male reproductive health.

Abusive use of anabolic androgenic steroids, male sexual dysfunction and infertility: an updated review

The evolving prevalence of anabolic androgenic steroids (AAS) abuse among nonathletes is alarming because of the known harm to an individual's health. Among the adverse effects of AAS abuse, male infertility and sexual dysfunction have been often reported in the literature, but little is known regarding its actual prevalence, possible underpinning mechanisms, and potential treatments either during or post-AAS usage. Thus, the current narrative review summarizes the state-of-art regarding the effects of AAS on male fertility and sexual function. Evidence was gathered from the latest reviews and recent original studies, specifically from prospective cohorts and clinical trials, ultimately resulting in five main topics of discussion. First, AAS usage is briefly characterized by its historical background, main physiological mechanisms, and the most frequently used AAS substances. Second, data on the prevalence of AAS-induced male infertility and sexual dysfunction are described. Third, some new insights on possible underpinning mechanisms of AAS-induced male infertility and sexual dysfunction are thoroughly discussed, with particular attention to histological data derived from animal models and the latest insights from prospective cohorts in humans. Fourth, the potential treatments during and after the AAS usage are presented, highlighting the odds of resolving male infertility and sexual dysfunction. Fifth, future directions on this topic are discussed, focusing on the methodological robustness of scientific studies.

Effects of Exercise on Testosterone and Implications of Drug Abuse: A Review

OBJECTIVE

Research points to exercise having a positive effect in fighting relapse and use of drugs of abuse. Through conducting this research, differences have been observed in the effects of exercise on drug abuse between sexes. Many of the studies found that exercise tends to cause a more profound effect in blocking drug relapse or reinstatement in males when compared with females.

METHODS

Our hypothesis is that these differences in response to drugs of abuse after an exercise regimen could in part be attributed to variations in testosterone levels between males and females.

RESULTS

Testosterone has been shown to have a modulatory impact on the dopaminergic activity in the brain, causing an effect on the brain's response to drugs of abuse. Exercise has demonstrated a causal effect on increasing testosterone levels in males, whereas drugs of abuse decrease testosterone levels in males.

CONCLUSIONS

Thus, exercise raising testosterone levels in males helps to decrease the dopaminergic response in the brain to drugs of abuse causing attenuation to drugs. To find sex-specific exercise treatments for drugs of abuse, it is important to continue researching exercise's efficacy against drugs of abuse.

Impact of anabolic androgenic steroids on male sexual and reproductive function: a systematic review

INTRODUCTION

Anabolic-androgenic steroids (AASs) are a complex cluster of synthetic derivatives of testosterone. AAS abuse is considered a major public health issue since it has increased among young/adolescent males. The use of steroids has a prevalence rate of 14% in young athletes and 30-75% in professional athletes or bodybuilders. AASs simulate the testosterone mechanism, binding the intracellular androgen receptor, and dysregulating the normal hypothalamic-pituitary-gonadal axis in the same way as exogenous testosterone. Abuse can produce several side effects on organs, such as the genital system. The physio-pathological mechanisms that cause AAS abuse-related, genital system disorders in humans are still not completely known.

EVIDENCE ACQUISITION

This study focuses on the effect of AASs on the male reproductive organs in humans and animals.

EVIDENCE SYNTHESIS

A systematic review was performed using SCOPUS, PubMed, Google Scholar, and Web of Sciences database up to 31 December 2021 using the keywords: "anabolic-androgenic steroids," "erectile dysfunction," "spermatogenesis" and "infertility;" (anabolic agents) "erectile dysfunction," "spermatogenesis" and "infertility." The review of the literature identified 66 articles published until 2021. Sixty-two articles were included. The use of AASs induces testicular atrophy and azoospermia known as "anabolic steroid-induced hypogonadism." Anabolic steroid induced infertility is characterized by oligo or azoospermia and abnormalities in sperm motility and morphology. Although sperm quality recovers in most cases within 4 months of stopping anabolic steroid abuse, the negative consequences on spermatogenesis can take up to 3 years to disappear. Human studies reported a positive correlation between AAS abuse in athletes and an increase in morphologically abnormal spermatozoa. Animal studies showed the destruction of Leydig cells and testicular atrophy in animals treated with cycles of AASs.

CONCLUSIONS

The present review of the literature highlights how little is known about the action of AASs on the male genital system. However, although their use is prohibited in many countries, the black market for these substances is still very frequent. The scientific landscape still has a lot to invest in the research of AAS on the male genital system to make young people even more aware of the negative aspects of these substances, contributing to the reduction of these products in an inappropriate way.

Downregulation of CYP17A1 by 20-hydroxyecdysone: plasma progesterone and its vasodilatory properties

Aim: To investigate the effect of 20-hydroxyecdysone on steroidogenic pathway genes and plasma progesterone, and its potential impact on vascular functions. Methods: Chimeric mice with humanized liver were treated with 20-hydroxyecdysone for 3 days, and hepatic steroidogenic pathway genes and plasma progesterone were measured by transcriptomics and GC–MS/MS, respectively. Direct effects on muscle and mesenteric arterioles were assessed by myography. Results: CYP17A1 was downregulated in 20-hydroxyecdysone-treated mice compared with untreated group (p = 0.04), with an insignificant increase in plasma progesterone. Progesterone caused vasorelaxation which was blocked by 60 mM KCl, but unaffected by nitric oxide synthase inhibition. Conclusion: In the short term, 20-hydroxyecdysone mediates CYP17A1 downregulation without a significant increase in plasma progesterone, which has a vasodilatory effect involving inhibition of voltage-dependent calcium channels, and the potential to enhance 20-hydroxyecdysone vasorelaxation.

Anabolic steroid misuse and male infertility: management and strategies to improve patient awareness

Introduction: Anabolic androgenic steroid use is an uncommon but important cause of male infertility. As paternal age and anabolic steroid use increases, providers are more likely than ever to encounter men with infertility and prior or concurrent anabolic steroid use. In this review, we outline the background, epidemiology and pathophysiology of anabolic steroid induced male infertility and provide recommendations regarding the diagnosis, management, and future prevention of this condition.Areas covered: Male reproductive physiology is a tightly regulated process that can be influenced by exogenous sources such as anabolic steroids and selective androgen receptor modulators (SARMs). Data suggest that a combination of selective estrogen receptor modulators (SERMs), human chorionic gonadotropin (hCG), aromatase inhibitors (AIs), and recombinant follicle-stimulating hormone (rFSH) may lead to spermatogenesis recovery.Expert opinion: Anabolic steroid and SARM users continue to exhibit lack of understanding regarding the potential side effects of their use on male fertility. Current literature suggests that spermatogenesis can be safely recovered using a combination of SERMs, hCG, AIs and rFSH although additional studies are necessary. While anabolic steroid prevention strategies have largely been focused on the individual level, further investigation is necessary and should be approached in a socioecological manner.

The physiology of male reproduction: Impact of drugs and their abuse on male fertility

Male factor accounts for about 30-50% of infertility. A common cause of male infertility is drug abuse; either illicit or prolonged use of prescribed drugs. This study provides a review of the physiology of the hypothalamic-pituitary-gonadal axis and recent literature on drugs that have been linked to male infertility and the associated mechanisms. Relevant peer-reviewed papers were assessed online using PubMed/PubMed Central, Scopus, AJOL, Google Scholar and DOAJ databases using Medical Subjects Headings (MeSH) indexes and relevant key word searches. Although drugs are beneficial when used at therapeutic levels, the abuse leads to impairment of hypothalamic-pituitary-gonadal functions, increased sperm DNA fragmentation and apoptosis, and reduced sperm quality. A good knowledge of the physiology of the hypothalamic-pituitary-gonadal axis and the influence of drugs on male fertility will guide healthcare providers in managing cases of infertility.

Cynara scolymus leaves extract alleviates nandrolone decanoate-induced alterations in testicular function and sperm quality in albino rats

Nandrolone decanoate (ND) is a commonly used anabolic-androgenic steroid. These drugs are illegally self-administered by athletes to enhance their sports performance. However, their abuse could influence the testicular function and fertility. The main objective of this study was to evaluate the possible protective effects of Cynara scolymus leaf extract (CLE) on ND-induced testicular dysfunction in rats. Five groups of adult male rats (10 rats each) were used. Group I rats received only saline and served as controls. Group II rats were injected with a vehicle once weekly, while group III rats received intramuscular injections of ND (20 mg/kg/week for 60 days). Group IV rats orally received 1 g/kg/day of CLE and group V rats received ND and CLE at the aforementioned doses. The results revealed that ND has a negative impact on the testicular function as evidenced by the significant increases (p ≤ 0.05) in testicular malondialdehyde concentration and serum non-prostatic acid phosphatase activity, as well as the significant decreases in serum testosterone levels, testicular weight, glutathione concentration, catalase enzyme activity, and total antioxidant capacity. These results were accompanied by considerable alterations of sperm characters and histopathological studies of the testicular tissue. However, co-treatment with CLE extract significantly alleviated (p ≤ 0.05) almost all ND-induced pathological alterations. In conclusion, co-treatment of ND-intoxicated rats with CLE ameliorated the toxic effects of ND on the testicular structure and function, probably due to its antioxidant activity.

Substance Abuse and Male Hypogonadism

Progressive deterioration of male reproductive function is occurring in Western countries. Environmental factors and unhealthy lifestyles have been implicated in the decline of testosterone levels and sperm production observed in the last fifty years. Among unhealthy lifestyles, substance and drug abuse is a recognized cause of possible alterations of steroidogenesis and spermatogenesis. Alcohol, opioids and anabolic-androgenic steroids are capable to reduce testosterone production in male interfering with testicular and/or hypothalamic-pituitary function. Other substances such as nicotine, cannabis, and amphetamines alter spermatogenesis inducing oxidative stress and subsequent apoptosis in testicular tissue. Substance and drug abuse is a potentially reversible cause of hypogonadism, defined as the failure of the testis to produce physiological concentrations of testosterone and/or a normal number of spermatozoa. The identification of the abuse is important because the withdrawal of substance intake can reverse the clinical syndrome. This review summarizes the most important clinical and experimental evidence on the effect of substance abuse on testosterone and sperm production.

Effects of non-contingent cocaine on 3alpha-androstanediol. I. Disruption of male sexual behavior

One of the hallmarks of drug abuse is a reduction in the salience of, and motivation for, natural rewards, such as mating. The effects of psychostimulants on male sexual interest and performance are conflicting; use of psychostimulants can produce increases in risky sexual behaviors but have detrimental effects on sexual ability. We hypothesize that these conflicting effects on sexual behavior are due to interactions between cocaine and androgens, such as testosterone and its neuroactive metabolite, 3α-androstanediol (3α-diol). Male rats were administered saline or cocaine (5, 10, or 20mg/kg, i.p.). Motor behavior was observed in the first 30min following drug-administration, and then sexual responding was assessed for 15min. Levels of androgens (testosterone, 3ɑ-diol, and testosterone's aromatized metabolite, estradiol) were measured in circulation and brain regions (frontal cortex, hippocampus, hypothalamus/striatum (hypo/str), and midbrain). Cocaine had no effect on measures of sexual interest (i.e. anogenital investigation). However, cocaine had substantial effects on consummatory sexual behaviors, such as the latency to mount/intromit and the number of sexual contacts. Frontal cortex and hypo/str 3α-diol levels were strongly correlated with consummatory behaviors in saline administered rats; however, this relationship was disrupted by cocaine at all dosages, concomitant with impaired sexual behaviors. Additionally, there was a shift in metabolism at low dosages of cocaine to push testosterone metabolism in the midbrain towards 3α-diol. On the contrary, moderate and high dosages of cocaine shifted testosterone metabolism towards estradiol. These data demonstrate that the association between cortical and hypo/str 3α-diol levels and sexual behavior of male rats is disrupted by non-contingent cocaine and that there may be dose-dependent effects of acute cocaine on androgen metabolism.

Anabolic steroids abuse and male infertility

For several decades, testosterone and its synthetic derivatives have been used with anabolic and androgenic purposes. These substances were first restricted to professional bodybuilders, but become more and more popular among recreational athletes. Up to date, 3,000,000 anabolic-androgenic steroids (AAS) users have been reported in the United States with an increasing prevalence, making AAS consumption a major public health growing concern. Infertility is defined by the WHO as the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse and a male factor is present in up to 50 % of all infertile couples. Several conditions may be related to male infertility.

Substance abuse, including AAS, is commonly associated to transient or persistent impairment on male reproductive function, through different pathways. Herein, a brief overview on AAS is offered. Steroids biochemistry, patterns of use, physiological and clinical issues are enlightened. A further review about fertility outcomes among male AAS abusers is also presented, including the classic reports on transient anabolic steroid-induced hypogonadism (ASIH), and the more recent experimental reports on structural and genetic sperm damage.

Mad men, women and steroid cocktails: a review of the impact of sex and other factors on anabolic androgenic steroids effects on affective behaviors

RATIONALE

For several decades, elite athletes and a growing number of recreational consumers have used anabolic androgenic steroids (AAS) as performance enhancing drugs. Despite mounting evidence that illicit use of these synthetic steroids has detrimental effects on affective states, information available on sex-specific actions of these drugs is lacking.

OBJECTIVES

The focus of this review is to assess information to date on the importance of sex and its interaction with other environmental factors on affective behaviors, with an emphasis on data derived from non-human studies.

METHODS

The PubMed database was searched for relevant studies in both sexes.

RESULTS

Studies examining AAS use in females are limited, reflecting the lower prevalence of use in this sex. Data, however, indicate significant sex-specific differences in AAS effects on anxiety-like and aggressive behaviors, interactions with other drugs of abuse, and the interplay of AAS with other environmental factors such as diet and exercise.

CONCLUSIONS

Current methods for assessing AAS use have limitations that suggest biases of both under- and over-reporting, which may be amplified for females who are poorly represented in self-report studies of human subjects and are rarely used in animal studies. Data from animal literature suggest that there are significant sex-specific differences in the impact of AAS on aggression, anxiety, and concomitant use of other abused substances. These results have relevance for human females who take these drugs as performance-enhancing substances and for transgender XX individuals who may illicitly self-administer AAS as they transition to a male gender identity.

Morphometric study of the corpus cavernosum after anabolic androgenic steroid administration in pubertal and adult rats

PURPOSE

To evaluate the penile morphological modifications of pubertal and adult rats chronically treated with supra-physiological doses of anabolic androgenic steroids.

METHODS

Forty-eight male Wistar rats were distributed into four groups: two control groups, 105- and 65-day-old (C105 and C65, respectively) injected with peanut oil (vehicle); and two treated groups, 105- and 65-day-old (T105 and T65, respectively) injected with nandrolone decanoate at a dose of 10 mg Kg-1 of body weight. The rats were injected once a week for eight weeks. The rats were then killed and their penises were processed for histomorphometric analyses. The mean of each parameter was statistically compared.

RESULTS

A corpus cavernosum reduction of 12.5% and 10.9% was observed in the T105 and T65 groups, respectively, when compared with their respective control groups. The cavernosum smooth muscle surface density diminished by 5.6% and 12.9% in the T65 and T105 groups, respectively, when compared with their controls. In contrast, the sinusoidal space increased by 17% in the T105 group and decreased by 9.6% in the T65 group.

CONCLUSION

The use of supra-physiological doses of AAS promotes structural changes in the rat penis, by altering the proportions of corpus cavernosum tissues, in both pubertal and adult treated animals.

Effect of different doses of nandrolone decanoate on lipid peroxidation, DNA fragmentation, sperm abnormality and histopathology of testes of male Wister rats

The present study aims of to investigate the effects of low and high doses of nandrolone decanoate (ND) on histopathology and apoptosis of the spermatogenic cells as well as lipid peroxidation, antioxidant enzyme activities, sperm abnormality and DNA fragmentation. Eighteen animals were divided into three groups each group contain six animals. The rats were divided into three groups as following: Group 1 was administered saline (control). Group 2, received nandrolone decanoate (3 mg/kg/weekly) (low dose) with intramuscular injection. Group 3, received intramuscular injection dose of nandrolone decanoate (10 mg/kg/weekly) (high dose). After 8 weeks, caspase-3 assay was used to determine the apoptotic cells. The sperm parameters, lipid peroxidation, antioxidant enzyme activities and testosterone concentration were also investigated in the experimental groups of both low and high dose compared to the control groups. Treated group with high dose showed degenerated germinal epithelial cells sloughed in the lumina of seminiferous tubules, where almost seminiferous tubules were devoid of spermatids and spermatozoa compared to control and group treated with low dose. Also, a significant increase of lipid peroxidation levels and heat shock proteins was observed in two groups administrated with two different doses of ND while, antioxidant enzyme activities, and testosterone concentration was significantly decreased in two treated group when compared with control. Administration of ND at high and low doses leads to deteriorated sperm parameters, DNA fragmentation and testicular apoptosis. In conclusion, the administration ND at high doses more effective on lipid peroxidation, antioxidant enzyme activities, sperm abnormality, histopathology, apoptotic and DNA changes compared to low dose group and to control group.

Anabolic-androgenic steroids and appetitive sexual behavior in male rats

Anabolic-androgenic steroids (AAS) increase libido and sexual behavior, but the underlying behavioral mechanisms are unclear. One way AAS may enhance expression of sexual behavior is by increasing the willingness to work for sex. In the present study, sexually-experienced male rats received daily injections of testosterone at supraphysiologic doses (7.5 mg/kg in water with 13% cyclodextrin) or vehicle and were tested for appetitive sexual behavior measured by operant responding for access to an estrous female. Initially, rats were trained in their home cage to respond on a nose-poke under a 10-min fixed-interval schedule for food reward. Once rats achieved stable response rates, the food was replaced by a female, followed by mating for 10 min. There was no effect of testosterone on operant responding for food (28.1 ± 4.4 responses/10 min for testosterone, 30.6 ± 4.3 for vehicle) or sex (35.0 ± 4.0 responses/10 min for testosterone, 37.3 ± 5.2 for vehicle). However, rats made significantly more responses for sex than for food (p < 0.05), and responses for food and sex were positively correlated among individuals (R(2) = 0.6). Additional groups of rats were trained to respond on a lever for the female under a 2nd-order schedule of reinforcement, where 5 responses opened a door to show the female for 5s. After 15 door openings, the male gained access to the female. There was no effect of testosterone on time to complete 75 responses: 38.4 ± 7.8 min for vehicle controls vs 43.3 ± 6.6 min for testosterone-treated rats (p > 0.05). These findings suggest that chronic high-dose testosterone does not enhance appetitive drive for sexual behavior.

Androgenic anabolic steroid exposure during adolescence: ramifications for brain development and behavior

This article is part of a Special Issue "Puberty and Adolescence". Puberty is a critical period for brain maturation that is highly dependent on gonadal sex hormones. Modifications in the gonadal steroid environment, via the use of anabolic androgenic steroids (AAS), have been shown to affect brain development and behavior. Studies in both humans and animal models indicate that AAS exposure during adolescence alters normal brain remodeling, including structural changes and neurotransmitter function. The most commonly reported behavioral effect is an increase in aggression. Evidence has been presented to identify factors that influence the effect of AAS on the expression of aggression. The chemical composition of the AAS plays a major role in determining whether aggression is displayed, with testosterone being the most effective. The hormonal context, the environmental context, physical provocation and the perceived threat during the social encounter have all been found to influence the expression of aggression and sexual behavior. All of these factors point toward an altered behavioral state that includes an increased readiness to respond to a social encounter with heightened vigilance and enhanced motivation. This AAS-induced state may be defined as emboldenment. The evidence suggests that the use of AAS during this critical period of development may increase the risk for maladaptive behaviors along with neurological disorders.

Sex-specific effect of the anabolic steroid, 17α-methyltestosterone, on inhibitory avoidance learning in periadolescent rats

The illicit use of anabolic androgenic steroids (AAS) has gained popularity among adolescents in the last decade. However, although it is known that exposure to AAS impairs cognition in adult animal models, the cognitive effects during adolescence remain undetermined. An inhibitory avoidance task (IAT) was used to assess the effect of AAS (17α-methyltestosterone; 17α-meT--7.5 mg/kg) in male and female periadolescent rats. A single injection of 17α-meT immediately before the footshock produced significant impairment of inhibitory avoidance learning in males but not females. Generalized anxiety, locomotion, and risk assessment behaviors (RAB) were not affected. Our results show that exposure to a single pharmacological dose of 17α-meT during periadolescence exerts sex-specific cognitive effects without affecting anxiety. Thus, disruption of the hormonal milieu during this early developmental period might have negative impact on learning and memory.

Anabolic-androgenic steroids induce apoptosis and NOS2 (nitric-oxide synthase 2) in adult rat Leydig cells following in vivo exposure

Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone (T) predominantly taken as drugs of abuse. Using in vivo treatment of adult male rats we investigated the effects of testosterone enanthate (TE) a widely abused AAS, on apoptosis of Leydig cells. Increased T and decreased luteinizing hormone levels in serum and decreased intra-testicular T values were found in 2 and 10 weeks treated groups. Two weeks of TE-treatment stimulated the expression of inducible nitric oxide synthase (NOS2) followed by increased NO production, decreased mitochondrial membrane potential and increased prevalence of Leydig cell apoptosis. This was prevented by in vivo administration of androgen receptor blocker. The induced NOS2 level and apoptosis returned to control levels after 10 weeks of TE-treatment but testes contained fewer Leydig cells. Overall, AAS in addition to reduced steroidogenesis induce transient increase of Leydig cells apoptotic rate through mechanism associated with androgen receptor, most likely involving NOS2 induction.

The androgenic anabolic steroid tetrahydrogestrinone produces dioxin-like effects via the aryl hydrocarbon receptor

For a long time, athletes have used androgenic anabolic steroids (AASs) in an inappropriate and veiled manner with the aim of improving exercise performance or for cosmetic purposes. Abuse of AASs triggers adverse effects such as hepatocarcinogenesis, heart attacks, and aggressive behavior. However, AAS-induced toxicity is not completely understood at the molecular level. In the present study, we showed, by performing a dioxin response element (DRE)-luciferase reporter gene assay, that tetrahydrogestrinone (THG), a popular and potent androgen receptor agonist, has dioxin-like effects. In addition, we showed that THG increased cytochrome P-450 1A1 (CYP1A1) mRNA and protein levels, and enzyme activity. The gene encoding CYP1A1 is involved in phase 1 xenobiotic metabolism and a target gene of the aryl hydrocarbon receptor (AhR). Using the AhR antagonist CH-223191, we also examined whether the effects of THG on DRE activation depended on AhR. Our results suggest that synthetic anabolic steroids may have dioxin-like side effects that can disturb endocrine systems and may cause other side effects including cancer through AhR.

Anabolic steroids and male infertility: a comprehensive review

What's known on the subject? and What does the study add? The negative impact of AAS abuse on male fertility is well known by urologists. The secondary hypogonadotropic hypogonadism is often highlighted when AAS and fertility are being discussed. On the other hand, the patterns of use, mechanisms of action and direct effects over the testicle are usually overseen. The present study reviews the vast formal and "underground" culture of AAS, as well as their overall implications. Specific considerations about their impact on the male reproductive system are made, with special attention to the recent data on direct damage to the testicle. To our knowledge this kind of overview is absolutely unique, offering a distinguished set of information to the day-by-day urologists. For several decades, testosterone and its synthetic derivatives have been used with anabolic and androgenic purposes. Initially, these substances were restricted to professional bodybuilders, becoming gradually more popular among recreational power athletes. Currently, as many as 3 million anabolic-androgenic steroids (AAS) users have been reported in the United States, and considering its increasing prevalence, it has become an issue of major concern. Infertility is defined as the failure to achieve a successful pregnancy after 12 months or more of regular unprotected intercourse, with male factor being present in up to 50% of all infertile couples. Several conditions may be related to male infertility. Substance abuse, including AAS, is commonly associated to transient or persistent impairment on male reproductive function, through different pathways. Herein, a brief overview on AAS, specially oriented to urologists, is offered. Steroids biochemistry, patterns of use, physiological and clinical issues are enlightened. A further review about fertility outcomes among male AAS abusers is also presented, including the classic reports on transient axial inhibition, and the more recent experimental reports on structural and genetic sperm damage.

Effects of anabolic androgenic steroids and social subjugation on behavior and neurochemistry in male rats

Early abuse and anabolic androgenic steroids (AAS) both increase aggression. We assessed the behavioral and neurochemical consequences of AAS, alone or in combination with social subjugation (SS), an animal model of child abuse. On P26, gonadally intact male rats began SS consisting of daily pairings with an adult male for 2 weeks followed by daily injections of the AAS, testosterone on P40. As adults, males were tested for sexual and aggressive behaviors towards females in various hormonal conditions and inter-male aggression in a neutral setting using home or opponent bedding. Neurotransmitter levels were assessed using HPLC. Results showed that AAS males displayed significantly more mounts toward sexually receptive, vaginally obstructed females (OBS) and displayed significantly more threats towards ovariectomized females. SS males mounted OBS females significantly less and were not aggressive toward females. The role of olfactory cues in a neutral setting did not affect aggression regardless of treatment. AAS significantly increased brainstem DOPAC and NE. SS decreased 5HIAA, DA, DOPAC, and NE in brainstem. 5HIAA was significantly increased in the prefrontal cortex of all experimental groups. We conclude that AAS and SS differentially affect behavior towards females as well as neurotransmitter levels.

Impact of anabolic androgenic steroids on adolescent males

Anabolic androgenic steroid (AAS) use increased dramatically among adolescent males. This review focuses on studies using animal models of AAS exposure during adolescence which is a hormonally sensitive developmental period. AAS exposure during this critical period has wide-ranging consequences, including increased dendritic spine density, altered brain serotonin levels and escalated aggression in response to physical provocation. Human data suggest that AAS induces indiscriminate and unprovoked aggression often described as "'roid rage". However, animal studies indicate that the behavioral impact of AAS is modulated by experiential and social contingencies, a perceived provocation, and the chemical composition of the AAS. The AAS, testosterone increases aggression in juvenile and adult male rats when physically provoked. In contrast, stanzolol, inhibits aggression in both juvenile and adult male rats, even when physically provoked. Nandrolone has minimal effects on aggression, unless preceded by attack training. Exposure to AAS during adolescence may have a host of unintended bio-behavioral consequences. Yet, the perception of harmlessness surrounds AAS use. The perception of harmlessness is promoted by the availability of AAS especially through internet pharmacies. The perception of acceptability is reflected in current cultural ethics that no longer condemn cheating to obtain personal achievement or success. A prevailing conviction is that although AAS are illegal they are not really bad. Reduction of the availability of AAS to adolescents requires ardent legislative and legal intervention. The problem of acceptability can be addressed by educating adolescents about the short-term and long-term effects of AAS on brain and behavior, to increase awareness of the potential consequences of AAS use that apply directly to them.

Prepubertal social subjugation and anabolic androgenic steroid-induced aggression in male rats

Abused children are more prone to abuse drugs, such as anabolic androgenic steroids (AAS), as teenagers and display violence as adults. AAS use has been linked with elevated aggression. Thus, exposure to child abuse and AAS may potentiate aggression. A social subjugation paradigm was used as an animal model of childhood abuse to determine whether prior subjugation increases AAS-induced aggression in male rats. Prepubertal gonadally intact male rats were exposed to social subjugation, a novel cage experience, or remained undisturbed in their home cages. Experimental males were socially subjugated by being placed in the home cage of an adult male. At puberty, both subjugated and nonsubjugated rats were injected with either the AAS testosterone or vehicle. AAS treatment continued for 5 weeks. Aggression was measured during the last week of AAS exposure. AAS was then discontinued. Aggression was again tested 12 weeks after AAS withdrawal. Aggression was tested under three conditions: (i) physical provocation of the experimental male; (ii) provocation of the intruder male; and (iii) without provocation. Both AAS-treated males and socially subjugated males displayed significantly more aggression than did controls. Elevated aggression by subjugated males was still present 17 weeks after social subjugation. AAS males also showed increased aggression 12 weeks after AAS withdrawal. However, exposure to both social subjugation and AAS had no long-term effects on aggression. The results of the present study indicate that social subjugation may have lasting consequences on the expression of adaptive social behaviours.

The effects of an anabolic androgenic steroid and low serotonin on social and non-social behaviors in male rats

The behavioral and neurochemical impact of low serotonin (5-HT) was examined in gonadally intact male rats exposed to an anabolic androgenic steroid (AAS) during puberty. Low 5-HT was induced beginning on postnatal day 26 using parachlorophylalanine (PCPA). Injections of the AAS, testosterone (TP), began on day 40. The rats were tested in both non-social (locomotor activity and nose poke for food) and social (low-threat and high-threat) contexts. PCPA and TP+PCPA significantly decreased locomotor activity. PCPA alone significantly increased nose poke latency compared to controls. Freezing in the PCPA group was significantly elevated compared to TP and TP+PCPA groups, but not compared to controls. AAS did not affect non-social behaviors. Thus, low serotonin may increase freezing in a non-social context. Following provocation, PCPA and TP+PCPA significantly increased aggression toward smaller non-threatening opponents, suggesting that males with low 5-HT are more aggressive in a low-threat context when provoked. In the resident-pair intruder test, TP significantly increased aggression whereas PCPA did not, suggesting that in a high-threat context, aggression is primarily mediated by AAS. TP+PCPA males were also significantly more aggressive in the high-threat context suggesting that exposure to AAS may override freezing behavior induced by low serotonin. Both PCPA and TP+PCPA significantly and substantially depleted 5-HT and 5-HIAA in all brain regions examined. AAS significantly decreased 5-HIAA levels in the hypothalamus and increased 5-HT levels in the frontal cortex. Following withdrawal from TP+PCPA, most behavioral and neurochemical measures returned to control levels. These data suggest that low serotonin may be a contributing factor in the increased aggression displayed by adolescents who abuse AAS.

Anabolic androgenic steroids differentially affect social behaviors in adolescent and adult male Syrian hamsters

Anabolic androgenic steroids (AAS) are synthetic derivatives of testosterone used by over half a million adolescents in the United States for their tissue-building potency and performance-enhancing effects. AAS also affect behavior, including reports of heightened aggression and changes in sexual libido. The expression of sexual and aggressive behaviors is a function of complex interactions among hormones, social context, and the brain, which is extensively remodeled during adolescence. Thus, AAS may have different consequences on behavior during adolescence and adulthood. Using a rodent model, these studies directly compared the effects of AAS on the expression of male sexual and aggressive behaviors in adolescents and adults. Male Syrian hamsters were injected daily for 14 days with either vehicle or an AAS cocktail containing testosterone cypionate (2 mg/kg), nandrolone decanoate (2 mg/kg), and boldenone undecylenate (1 mg/kg), either during adolescence (27-41 days of age) or in adulthood (63-77 days of age). The day after the last injection, males were tested for either sexual behavior with a receptive female or agonistic behavior with a male intruder. Adolescent males treated with AAS showed significant increases in sexual and aggressive behaviors relative to vehicle-treated adolescents. In contrast, AAS-treated adults showed significantly lower levels of sexual behavior compared with vehicle-treated adults and did not show heightened aggression. Thus, adolescents, but not adults, displayed significantly higher behavioral responses to AAS, suggesting that the still-developing adolescent brain is more vulnerable than the adult brain to the adverse consequences of AAS on the nervous system and behavior.

Anabolic androgens restore mating after sexual satiety in male rats

Androgen receptors and estrogen receptors importantly participate in the neuroendocrine control of masculine mating behavior. Sexual satiety is the long term inhibition of masculine mating behavior after repeated ejaculations and is associated to changes in both androgen receptor and estrogen receptor-alpha expression. Androgen receptor expression is up-regulated by systemic chronic administration of anabolic androgens, 5alpha-dihydrotestosterone or estradiol benzoate. This study was carried out to investigate the effect of these treatments on sexual satiety development and recovery; additionally flutamide or tamoxifen treatments -- alone or together with anabolic androgens -- were also included. Chronic 15-day treatment with 5alpha-dihydrotestosterone (5 mg/kg) or tamoxifen (15 mg/kg) inhibited, whereas estradiol benzoate treatment (5 mg/kg) facilitated, mating behavior during sexual satiety development. The proportion of animals that ejaculated 48 h after sexual satiety was increased after 17-day treatment with a mixture of anabolic androgens containing 2 mg/kg testosterone propionate, 2 mg/kg nandrolone decanoate and 1 mg/kg boldenone undecylenate. This effect was only blocked by the combined administration of flutamide plus tamoxifen. The data suggest that anabolic androgens metabolites synergize to restore mating behavior after sexual satiety.

Pubertal exposure to anabolic androgenic steroids increases spine densities on neurons in the limbic system of male rats

Human studies show that the number of teenagers abusing anabolic androgenic steroids (AAS) is increasing. During adolescence, brain development is altered by androgen exposure, which suggests that AAS may potentially alter central nervous system (CNS) development. The goal of the present study was to determine whether pubertal AAS exposure increased dendritic spine densities on neurons within the medial amygdala and the dorsal hippocampus. Pubertal gonadally intact male rats received the AAS testosterone propionate (5 mg/kg) or vehicle for 5 days/week for 4 weeks. To determine the long-term implications of pubertal AAS use, another set of males received the same AAS treatment and was then withdrawn from AAS exposure for 4 weeks. Results showed that pubertal AAS exposure significantly increased spine densities on neurons in the anterior medial amygdala, posterodorsal medial amygdala, and the cornu ammonis region 1 (CA1) of the hippocampus compared with gonadally intact control males. Spine densities returned to control levels within the anterior medial amygdala and the posterodorsal medial amygdala 4 weeks after withdrawal. However, spine densities remained significantly elevated after AAS withdrawal in the CA1 region of the hippocampus, suggesting that pubertal AAS exposure may have a long-lasting impact on CA1 hippocampal neuroanatomy. Since pubertal AAS exposure increased spine densities and most excitatory synapses in the CNS occur on dendritic spines, AAS may increase neuronal excitation. It is proposed that this increase in excitation may underlie the behavioral responses seen in pubertal AAS-treated male rats.

Effects of anabolic androgenic steroids on the development and expression of running wheel activity and circadian rhythms in male rats

In humans, anabolic androgenic steroid (AAS) use has been associated with hyperactivity and disruption of circadian rhythmicity. We used an animal model to determine the impact of AAS on the development and expression of circadian function. Beginning on day 68 gonadally intact male rats received testosterone, nandrolone, or stanozolol via constant release pellets for 60 days; gonadally intact controls received vehicle pellets. Wheel running was recorded in a 12:12 LD cycle and constant dim red light (RR) before and after AAS implants. Post-AAS implant, circadian activity phase, period and mean level of wheel running wheel activity were compared to baseline measures. Post-AAS phase response to a light pulse at circadian time 15 h was also tested. To determine if AAS differentially affects steroid receptor coactivator (SRC) expression we measured SRC-1 and SRC-2 protein in brain. Running wheel activity was significantly elevated by testosterone, significantly depressed by nandrolone, and unaffected by stanozolol. None of the AAS altered measures of circadian rhythmicity or phase response. While SRC-1 was unaffected by AAS exposure, SRC-2 was decreased by testosterone in the hypothalamus. Activity levels, phase of peak activity and circadian period all changed over the course of development from puberty to adulthood. Development of activity was clearly modified by AAS exposure as testosterone significantly elevated activity levels and nandrolone significantly suppressed activity relative to controls. Thus, AAS exposure differentially affects both the magnitude and direction of developmental changes in activity levels depending in part on the chemical composition of the AAS.

The reversibility of sperm quality after discontinuing nandrolone decanoate in adult male rats

AIM

To investigate the reversibility of the effect of nandrolone decanoate (ND) on sperm parameters after discontinuing the drug.

METHODS

Three groups of rats received peanut oil (control), low and high doses of ND for 14 weeks, respectively. Each group was divided into subgroups A and B, in which rats were killed 14 and 28 weeks after initiating the injection, respectively.

RESULTS

Sperm count and motile sperm fraction were decreased in the subgroups A and B that received low and high doses of ND in comparison with the controls A and B, respectively. The sperm count and motile sperm fraction increased in the subgroups B that received low and high doses of ND in comparison with their corresponding subgroups A. The number of normal morphology sperm was decreased significantly in subgroups A receiving low and high doses of ND in comparison with the control subgroup A. However, this parameter was not decreased in subgroups B receiving low and high doses in comparison with the control subgroup B. The normal sperm morphology did not show any significant differences in the subgroups B in comparison with their corresponding subgroups A.

CONCLUSION

The 14-week injection of low and high doses of ND decreases sperm quality and quantity in rats. These parameters were improved after discontinuing ND, but not recovered completely even when they are left untreated for 14 weeks.

Behavioral effects of pubertal anabolic androgenic steroid exposure in male rats with low serotonin

The goal of this study was to assess the interactive effects of chronic anabolic androgenic steroid (AAS) exposure and brain serotonin (5-hydroxytryptamine, 5-HT) depletion on behavior of pubertal male rats. Serotonin was depleted beginning on postnatal day 26 with parachlorophenylalanine (PCPA 100 mg/kg, every other day); controls received saline. At puberty (P40), half the PCPA-treated rats and half the saline-treated rats began treatment with testosterone (T, 5 mg/kg, 5 days/week). Behavioral measures included locomotion, irritability, copulation, partner preference, and aggression. Animals were tested for aggression in their home cage, both with and without physical provocation (mild tail pinch). Brain levels of 5-HT and its metabolite, 5-hydroxyindoleacetic acid (5-HIAA), were determined using HPLC. PCPA significantly and substantially depleted 5-HT and 5-HIAA in all brain regions examined. Chronic T treatment significantly decreased 5-HT and 5-HIAA in certain brain areas, but to a much lesser extent than PCPA. Chronic exposure to PCPA alone significantly decreased locomotor activity and increased irritability but had no effect on sexual behavior, partner preference, or aggression. T alone had no effect on locomotion, irritability, or sexual behavior but increased partner preference and aggression. The most striking effect of combining T+PCPA was a significant increase in attack frequency as well as a significant decrease in the latency to attack, particularly following physical provocation. Based on these data, it can be speculated that pubertal AAS users with low central 5-HT may be especially prone to exhibit aggressive behavior.

Stereological study of the effects of nandrolone decanoate on the rat prostate

It has been shown that nandrolone decanoate which is one of the anabolic-androgenic steroid compounds changes the testis structure and sperm quality but quantitative studies of the prostate have received less attention. Control rats received the peanut oil and experimental group received nandrolone decanoate for 14 weeks. Then the rats were left untreated for 14 weeks. After 14 weeks of withdrawal, the prostate was studied using stereological methods. The mean prostate weight decreased approximately 39% (p<0.009) in nandrolone decanoate treated rats. The mean total prostate volume, glands, epithelia, fluids and collagen bundles reduced approximately 30% (p<0.03), approximately 31% (p<0.03), approximately 41% (p<0.02), approximately 31% (p<0.05) and approximately 59.5% (p<0.02) in the experimental group. The mean total luminal surface of the glands and total length of the vessels decreased approximately 40% (p<0.02) and approximately 46% (p<0.009), respectively, in the nandrolone decanoate treated rats. The height of epithelium did show no difference. It can be concluded that nandrolone decanoate causes atrophic changes in the components of rat prostate.

Stacking anabolic androgenic steroids (AAS) during puberty in rats: A neuroendocrine and behavioral assessment

Anabolic androgenic steroid (AAS) abuse is increasing in teenagers. We examined the effects of stacked AAS in adolescent male rats. Stacking, in which multiple AAS are taken simultaneously, is commonly employed by humans. Beginning at puberty gonadally intact male rats received testosterone, nandrolone, or stanozolol. Additional groups received stacked AAS: testosterone + stanozolol, nandrolone + stanozolol, or nandrolone + testosterone. Injections continued during tests for sexual behavior, vocalizations, scent marking, partner preference, aggression and fertility. Body and reproductive tissue weights were taken. Sexual and aggressive behaviors were increased by testosterone yet inhibited by stanozolol; nandrolone had no effect. Stacking testosterone with stanozolol prevented the inhibitory effects of stanozolol. Body weight was decreased by testosterone and all stacked AAS. Cell nuclear androgen receptor binding in brain was significantly increased in nandrolone males and decreased in stanozolol males; testosterone males were slightly higher than controls. Androgen receptors in stacked groups were intermediate between individual AAS suggesting that stanozolol competed with other AAS for androgen receptors despite its low affinity. The results indicate that stacking AAS influences the effects of individual AAS on behavioral and endocrine measures, and levels of androgen receptor occupation are not directly correlated with AAS effects on behavior.

High doses of nandrolone decanoate reduce volume of testis and length of seminiferous tubules in rats

Anabolic-androgenic steroid (AAS) compounds rank among the drugs most widely abused with the goal of improving athletic ability, appearance, or muscle mass. It has been shown that these compounds have adverse effects on human and animal physiology and sperm quality, but quantitative structural changes of the testis have received less attention. The present study was conducted to evaluate the effects of nandrolone decanoate, which is one of the AAS compounds, on testis weight and volume, diameter and length of seminiferous tubules in rats by unbiased stereological methods. Adult rats were divided into three groups. The first comprised control rats; the second and third groups received low and high doses of nandrolone decanoate for 14 weeks. The rats were then left untreated for 14 weeks. After removal of the testis, stereological study of these tissues showed that the mean volume of testis and length of the seminiferous tubules in the animals that received high doses of nandrolone decanoate were reduced approximately 32% (p<0.01) and approximately 31% (p<0.04), respectively, in comparison with the control group. It can be concluded that the high doses of nandrolone decanoate produce structural changes in the rat testis that remain 14 weeks after stopping injection of the drug.

Reinforcing aspects of androgens

Are androgens reinforcing? Androgenic-anabolic steroids (AAS) are drugs of abuse. They are taken in large quantities by athletes and others to increase performance, often with negative long-term health consequences. As a result, in 1991, testosterone was declared a controlled substance. Recently, Brower [K.J. Brower, Anabolic steroid abuse and dependence. Curr. Psychiatry Rep. 4 (2002) 377-387.] proposed a two-stage model of AAS dependence. Users initiate steroid use for their anabolic effects on muscle growth. With continued exposure, dependence on the psychoactive effects of AAS develops. However, it is difficult in humans to separate direct psychoactive effects of AAS from the user's psychological dependence on the anabolic effects of AAS. Thus, studies in laboratory animals are useful to explore androgen reinforcement. Testosterone induces a conditioned place preference in rats and mice, and is voluntarily consumed through oral, intravenous, and intracerebroventricular self-administration in hamsters. Active, gonad-intact male and female hamsters will deliver 1 microg/microl testosterone into the lateral ventricles. Indeed, some individuals self-administer testosterone intracerebroventricularly to the point of death. Male rats develop a conditioned place preference to testosterone injections into the nucleus accumbens, an effect blocked by dopamine receptor antagonists. These data suggest that androgen reinforcement is mediated by the brain. Moreover, testosterone appears to act through the mesolimbic dopamine system, a common substrate for drugs of abuse. Nonetheless, androgen reinforcement is not comparable to that of cocaine or heroin. Instead, testosterone resembles other mild reinforcers, such as caffeine, nicotine, or benzodiazepines. The potential for androgen addiction remains to be determined.

Long-term effects of pubertal anabolic-androgenic steroid exposure on reproductive and aggressive behaviors in male rats

The current study examined acute and long-term effects of anabolic-androgenic steroid (AAS) exposure during puberty on copulation, vocalizations, scent marking, and intermale aggression, both with and without tail pinch, in intact male rats. Animals received 5 mg/kg of testosterone, nandrolone, stanozolol, or vehicle, beginning at puberty. After 5 weeks, behavior tests were performed while continuing AAS injections. AAS treatment was then discontinued. Behaviors were tested during 3-5 weeks, 9-11 weeks, and 15-17 weeks of withdrawal. During AAS administration, stanozolol males showed significant reductions in all behaviors compared with controls, except aggression with tail pinch. Nandrolone treatment significantly reduced vocalizations and scent marking, and testosterone had no significant effect on behavior. During withdrawal, behaviors in stanozolol males recovered to control levels at variable rates: aggression at 4 weeks; mounts, vocalizations, and scent marking at 9 weeks; and ejaculations at 15 weeks of withdrawal. Stanozolol males showed significantly higher levels of tail pinch-induced aggression during every withdrawal test. Nandrolone-treated males scent-marked at control levels by 9 weeks withdrawal but displayed significantly fewer vocalizations and significantly more tail pinch-induced aggression than controls for the entire study. Testosterone-treated males scent-marked significantly below controls at 3 weeks withdrawal and showed significantly more tail pinch-induced aggression at 5 weeks withdrawal. All three AAS significantly increased tail pinch-induced aggression compared with corresponding nontail pinch tests, even at study endpoint. These results suggest that alterations in androgen-dependent behaviors by pubertal AAS exposure can persist long after drug exposure, and some effects may even be permanent.

Behavioral and physiological responses to anabolic-androgenic steroids

Anabolic-androgenic steroids (AAS) are synthetic derivatives of testosterone originally designed for therapeutic uses to provide enhanced anabolic potency with negligible androgenic effects. Although AAS continue to be used clinically today, the medical benefits of low therapeutic doses of AAS stand in sharp contrast to the potential health risks associated with the excessive doses self-administered not only by elite athletes and body builders, but by a growing number of recreational users, including adolescent boys and girls. The deleterious effects of AAS on peripheral organs and the incidence of altered behaviors in AAS abusers have been well documented in a number of excellent current reviews for clinical populations. However, a comparable synthesis of nonclinical studies has not been made. Our purpose in this review is to summarize the literature for animal models of the effects of supraphysiological doses of AAS (e.g. those that mimic human abuse regimes) on behaviors and on the neural circuitry for these behaviors. In particular, we have focused on studies in rodents that have examined how AAS alter aggression, sexual behaviors, anxiety, reward, learning, and locomotion and how AAS alter the expression and function of neurotransmitter systems and other signaling molecules that underlie these behaviors.

Effects of pubertal anabolic-androgenic steroid (AAS) administration on reproductive and aggressive behaviors in male rats

Adolescence in human males is a hormonally sensitive period when many adult behaviors develop, including sexual and aggressive behaviors. Using a rat model, the authors examined the effects of three anabolic-androgenic steroids (AAS) during puberty: testosterone, nandrolone, and stanozolol. Copulation, vocalizations, scent-marking, and aggression were tested following AAS exposure. Relative to gonadally intact controls, rats injected with testosterone showed a significant increase in scent-marking and aggression in the opponent's home cage. Nandrolone had no effect. Stanozolol significantly inhibited all behaviors. Results suggest that depending on the chemical structure of the steroid, AAS exposure during puberty affects several androgen-dependent behaviors. Because adolescence in humans is a period of hormonal change, abuse of AAS, particularly stanozolol, during this time may disrupt the establishment of normal adult behavior patterns.