Nicotine and cotinine inhibit steroidogenesis in mouse Leydig cells

Two modified density gradient centrifugation methods facilitate the isolation of mouse Leydig cells

Preparation of sufficient mouse Leydig cells (LCs) with high purity is a prerequisite for investigations of the biological/pathological functions of LCs in mouse models. Density gradient centrifugation based on discontinuous Percoll gradients is an effective method (defined as regular method) for LC isolation. In this study, we developed two modified methods for LC isolation and compared their performance with that of the regular method. Modified method 1 integrated the crude LCs into the 50% Percoll solution before centrifugation. Modified method 2 sequentially used 50 and 60% Percoll solutions to isolate LCs. The purity of LCs was approximately 88.4, 91.3, and 79.7% derived from the regular, modified 1, and modified 2 methods, respectively. The yields of LCs in the same respective order were approximately 1.7 × 10⁵, 3.9 × 10⁵, and 11.9 × 10⁵ cells per 10⁸ interstitial cells input. Modified method 1 attained higher purity and yields than those of the regular method. Although the purity of LCs was relatively low for modified method 2, it could be used before further purification by, for example, fluorescence-activated or magnetic-activated cell sorting, owing to its simplicity and high yields. Therefore, our study provided alternative methods to facilitate LC isolation in mice.

Testosterone and testicular changes in F1 offspring of Wistar rats maternally exposed to nicotine during gestation

OBJECTIVES

This study aimed to determine the effect of intrauterine exposure to nicotine in the first fourteen days of gestation on the testicular function of male Wistar rats.

METHODS

Pups of both control and nicotine-treated groups were selected and sacrificed on day 60 after birth. Birth weight, weight of reproductive organs, hormonal profile, and histopathology were determined in the first filial (F1) generation.

RESULTS

Significant decreases in birth weight and litter size were found in the pups treated with nicotine when compared with the animals in the control group. Significant decreases were also observed in the testicular weight of nicotine-treated rats, but not in epididymal weight, when compared to controls. Testosterone levels were significantly decreased, atrophy was observed in the genital epithelial cells, and distortions were noted in the testes of nicotine-treated F1 males.

CONCLUSION

These results suggest that nicotine exposure during pregnancy may cause endocrine disruption, and thus produce deleterious effects on offspring reproductive function.

The influence of smoking and cessation on the human reproductive hormonal balance

Smoking is the most widespread substance dependence in the world. Nicotine and some other components of the cigarette smoke cause various endocrine imbalances, and have negative effects on pituitary, thyroid, adrenal, testicular and ovarian functions. Here, we examined studies that describe the influence of smoking and smoking cessation on the male and female reproductive systems. We also focused on studies providing an account of differences in cessation success rates between men and women. In men, the most common effects associated with smoking are erectile dysfunction and decreasing spermiogram quality. Several groups have studied the effects of cigarette smoking on testosterone levels in men. However, the results have been conflicting. In women, nicotine has an anti-estrogen effect and increases the ratio of androgens to estrogens throughout life. Beside nicotine, other cigarette toxins also cause dysregulation of reproductive and hormonal system, and essentially influence the probability of a successful pregnancy not only in cases of assisted reproduction but also in healthy women. Tobacco addiction is one of the forms of addiction that are generally thought to be different for men and for women. Women are less successful than men in quitting smoking, and nicotine replacement therapy is less effective in female smokers. We also summarize recent studies that have indicated possible reasons.

Testicular cells exhibit similar molecular responses to cigarette smoke condensate ex vivo and in vivo

Male exposure to cigarette smoke is associated with seminal defects and with congenital anomalies and childhood cancers in offspring. In mice, paternal exposure to cigarette smoke condensate (CSC) causes molecular defects in germ cells and phenotypic effects in their offspring. Here we used an ex vivo testicular explant model and in vivo exposure to determine the concentration at which CSC impairs spermatogenesis and offspring development. We explanted testis tissue at postnatal day (P)5.5 and cultured it until P11.5. Assessment of growth parameters by analyzing expression of cell-specific markers revealed that the explant system maintained structural and functional integrity. We exposed the P5.5 to -11.5 explants to various concentrations (40-160 µg/ml) of CSC and confirmed that nicotine in the CSC was metabolized to cotinine. We assessed various growth and differentiation parameters, as well as testosterone production, and observed that many spermatogenesis features were impaired at 160 µg/ml CSC. The same parameters were impaired by a similar CSC concentration in vivo Finally, females mated to males that were exposed to 160 µg/ml CSC neonatally had increased rates of pup resorption. We conclude that male exposure to CSC impairs offspring development and that the concentration at which CSC impairs spermatogenesis is similar in vivo and ex vivo. Given that the concentrations of CSC we used contained similar doses of nicotine as human smokers are exposed to, we argue that our model mimics human male reproductive effects of smoking.-Esakky, P., Hansen, D. A., Drury, A. M., Felder, P., Cusumano, A., Moley, K. H. Testicular cells exhibit similar molecular responses to cigarette smoke condensate ex vivo and in vivo.

The steroid spectrum during and after quitting smoking

Addiction to tobacco results in an imbalance of endocrine homeostasis in both sexes. This can also have impacts on fertility problems. The male reproductive system is less susceptible than that of females, with a worsening spermiogram in smokers, the most cited effect in the literature. However, the literature is inconsistent as to the effects of smoking on steroid hormone levels in men, and there is very little data on the effects of quitting smoking in men. In this study we followed 76 men before quitting smoking, and then after 6, 12, and 24 weeks and 1 year of abstinence. We measured basic anthropomorphic data and steroid hormone levels along with steroid neuroactive metabolites using GC-MS. We demonstrate lower androgen levels in men who smoke, and these changes worsened after quitting smoking. There was a drop in SHBG already in the first week of non-smoking, and levels continued to remain low. Male smokers have lower androgen levels compared to non-smokers. The lower the initial level of androgen, the lower the likelihood of success in quitting smoking. Changes in steroid hormones proved to be a promising marker for the prediction of success in quitting smoking.

Time-course of extracellular nicotine and cotinine levels in rat brain following administration of nicotine: effects of route and ethanol coadministration

RATIONALE

Nicotine and ethanol are commonly coabused drugs, and nicotine-laced ethanol products are growing in popularity. However, little is known about time-course changes in extracellular nicotine and cotinine levels in rat models of ethanol and nicotine coabuse.

OBJECTIVES

The objective of the present study was to determine the time-course changes in brain levels of nicotine and cotinine following subcutaneous (SC) and intragastric (IG) nicotine administration in alcohol-preferring (P) and Wistar rats.

METHODS

In vivo microdialysis was used to collect dialysate samples from the nucleus accumbens shell (NACsh) for nicotine and cotinine determinations, following SC administration of (-)-nicotine (0.18, 0.35, and 0.70 mg/kg) in female P and Wistar rats or IG administration of (-)-nicotine (0.35 and 0.70 mg/kg) in 15 % (v/v) ethanol or water in female P rats.

RESULTS

SC nicotine produced nicotine and cotinine dialysate levels as high as 51 and 14 ng/ml, respectively. IG administration of 15 % EtOH + 0.70 mg/kg nicotine in P rats resulted in maximal nicotine and cotinine dialysate levels of 19 and 14 ng/ml, respectively, whereas administration of 0.70 mg/kg nicotine in water resulted in maximal nicotine and cotinine levels of 21 and 25 ng/ml, respectively. Nicotine and cotinine levels were detectable within the first 15 and 45 min, respectively, after IG administration.

CONCLUSIONS

Overall, the results of this study suggest that nicotine is rapidly adsorbed and produces relevant extracellular brain concentrations of nicotine and its pharmacologically active metabolite, cotinine. The persisting high brain concentrations of cotinine may contribute to nicotine addiction.

Toxicity of gutkha, a smokeless tobacco product gone global: is there more to the toxicity than nicotine?

The popularity of smokeless tobacco (ST) is growing rapidly and its prevalence of use is rising globally. Consumption of Gutkha, an addictive form of ST, is particularly common amongst South Asian communities throughout the World. This includes within the US, following large-scale immigration into the country. However, there exists a lack of knowledge concerning these alternative tobacco products. To this end, a study was carried out to determine the toxicity of gutkha, and what role, if any, nicotine contributes to the effects. Adult male mice were treated daily for 3-week (5 day/week, once/day), via the oral mucosa, with equal volumes (50 μL) of either sterile water (control), a solution of nicotine dissolved in water (0.24 mg of nicotine), or a solution of lyophilized guthka dissolved in water (21 mg lyophilized gutkha). Serum cotinine, measured weekly, was 36 and 48 ng/mL in gutkha- and nicotine-treated mice, respectively. Results demonstrated that exposure to nicotine and gutkha reduced heart weight, while exposure to gutkha, but not nicotine, decreased liver weight, body weight, and serum testosterone levels (compared to controls). These findings suggest that short-term guhtka use adversely impacts growth and circulating testosterone levels, and that gutkha toxicity may be driven by components other than nicotine. As use of guthka increases worldwide, future studies are needed to further delineate toxicological implications such that appropriate policy decisions can be made.

Nicotine alters male reproductive hormones in male albino rats: The role of cessation

OBJECTIVES

The use of nicotine through smoking remains a serious health problem. It has been associated with reduced fertility, although the mechanism responsible is still unclear. The present study was designed to investigate whether nicotine-induced infertility is associated with altered male reproductive hormones in male albino rats.

MATERIALS AND METHODS

Forty male rats were divided equally into five groups and treated orally for thirty days. Group I, which served as the control received 0.2 ml/kg normal saline, Group II and III received 0.5 mg/kg (low dose) and 1.0 mg/kg (high dose) body weight of nicotine, respectively. The fourth and fifth groups were gavaged with 0.5 mg/kg and 1.0 mg/kg body weight of nicotine but were left untreated for another 30 days. These groups served as the recovery groups. Serum was analyzed for testosterone, luteinizing hormone (LH), follicle stimulating hormones (FSH), and prolactin using radioimmunoassay.

RESULTS

Results showed that nicotine administration significantly decreased (P < 0.05) testosterone in the low and high treated groups and FSH in the high dose treated group when compared with the control group. There was a significant increase (P < 0.05) in mean LH and prolactin level in the high dose treated group when compared with the control. However, the values of the recovery groups were comparable with the control.

CONCLUSION

The findings in this study suggest that nicotine administration is associated with distorted reproductive hormones in male rats although ameliorated by nicotine cessation. It is plausible that the decreased testosterone level is associated with testicular dysfunction rather than a pituitary disorder.

Effects of smoking cessation on hormonal levels in men

Chronic smoking can cause imbalance in endocrine homeostasis and impairment of fertility in both sexes. The male reproductive system is more resilient, still the literature provides conflicting results about the influence of smoking on the steroid hormone levels. The data about smoking cessation are limited; there has not yet been a study primarily focused on changes in steroids levels. In our study, we analyzed levels of testosterone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulphate (DHEAS), cortisol and sex hormone-binding globulin (SHBG) in male smokers and during smoking cessation. Monitored analytes were determined by RIA. The free testosterone index was calculated. Basal samples of men successful and unsuccessful in smoking cessation did not differ and monitored hormones could hardly predict success of smoking cessation. After one year without smoking, a significant BMI increase and SHBG decrease in former smokers was observed. The decrease in total testosterone was non-significant. Changes in SHBG and testosterone did not correlate with BMI, presumably due to the direct effect of smoking cessation.

Effect of nicotine on spermatogenesis in adult albino rats

This study aimed to assess the effects of nicotine on spermatogenesis in 140 mature male albino rats divided into group A (controls), group B (sham controls), group C (nicotine treated) and group D (nicotine withdrawal). Group C was subdivided into CI, CII, CIII according to the dose of injected nicotine (0.2, 0.4 and 0.6 mg nicotine per 100 g per day), where each subgroup was further subdivided according to the treatment duration into subgroups a, b and c that received nicotine for 2, 4 and 8 weeks. Group D received nicotine for 8 weeks followed by withdrawal for another 8 weeks to assess testicular recovery. Testicular tissue sections were subjected to haematoxylin and eosin, Masson's trichrome stains and morphometry. The results showed that nicotine caused degenerative changes in the seminiferous tubules, revealed by altered general tubular architecture, decreased thickness of the spermatogenic cell masses, Sertoli cell vacuolation and thickened basal lamina. These changes were proportional to the nicotine dose and duration. Following nicotine withdrawal, regeneration of the damaged seminiferous tubules was observed to be rather complete in CI group. It is concluded that nicotine could adversely affect testicular spermatogenesis in a dose- and time-dependent manner which would be almost reversible after nicotine withdrawal, especially after small doses.

Reproductive toxic potential of panmasala in male Swiss albino mice

Some ingredients of panmasala have the ability to penetrate the blood-testis barrier but the reproductive toxic potential of panmasala has not been studied. This study is aimed to assess the possible damage caused by panmasala to male reproductive system in mice. Swiss albino male mice were randomly divided into 7 groups receiving either standard control diet or panmasala-containing diet. Three doses (0.5%, 1.5% and 3%) of panmasala plain (PMP) as well as panmasala with tobacco (PMT)—gutkha were given for a period of 6 months. Assessment of organ weight, sperm count and morphology, spermatid count, sperm production, testicular 17β-hydroxysteroid dehydrogenase (17β-HSD) activity and histology were conducted. A nonsignificant decrease in absolute and relative weight of testis and epididymis was observed. Spermatid count, sperm count and production were significantly decreased and 17β-HSD activity was found considerably declined at 3% of both PMP- and PMT-treated groups as compared to control. The histological observations revealed panmasala induced testicular damage. Abnormal morphology of sperm head shape was significantly elevated in higher doses of both types of panmasala-treated groups than control. The results suggests that panmasala has reproductive toxic potential and more alteration is seen with gutkha as compared to panmasala plain, indicating that similar effects might also be possible in humans.

Withdrawal from chronic nicotine in adolescent and adult rats

The purpose of the present experiment is to assess potential differences in nicotine withdrawal in both adolescent and adult rats. Nicotine dependence was induced via osmotic minipump in adolescent rats (releasing 22.2 mg/kg/day on Postnatal Day 28) and adults (release rate of 18.4 mg/kg/day on Postnatal Day 60); differential initial release rates were used across age to compensate for the more rapid weight gain of adolescents. On Day 7 of nicotine exposure, withdrawal was induced via the administration of a nicotinic antagonist, mecamylamine (1.0 mg/kg i.p.), and withdrawal-induced anxiogenesis assessed on the elevated plus maze. On Days 1 and 4 after pump removal, animals were examined for startle responses and prepulse inhibition in an acoustic startle chamber. Adult animals exhibited a nicotine withdrawal-induced increase in anxiety, while adolescents did not. One day following the removal of minipumps, only nicotine dependent adolescent animals exhibited a disruption in prepulse inhibition. Nicotine withdrawal failed to produce an alteration in acoustic startle response in either group. Together these data suggest that ontogenic differences in nicotine withdrawal are dependent on the withdrawal measure examined, with adolescents being less sensitive than adults to anxiety-like symptoms, while being more sensitive to withdrawal-induced cognitive disruption.

Effects of aqueous extracts of "Betel quid" and its constituents on testosterone production by dispersed mouse interstitial cells

Betel quid (BQ) is a favorite chewing item among many communities in different parts of Asia where it is popular by different names. BQ is a unique combination of nut or fruit from the Areca catechu Linn. (AN) tree, leaf from the Piper betle Linn. (BL) vine, slaked lime, paste of bark from the Acacia catechu tree and other spices. AN has been used successfully in various traditional medicines by different civilizations over several ages. Initially condemned by the medical communities for its health hazards, identification and application of potent pharmacologically bioactive compounds from different constituents of BQ have rekindled growing interest in related investigations. Curious about the stimulating role of BQ, we investigated the potential steroidogenic activity of hot water extract from BQ and its constituents and arecoline on testosterone producing ability in an in vitro experiment. Enzyme dissociated interstitial cells from adult mouse testes (ICR strain) were cultured with/without different doses of the extracts and the level of testosterone produced was assayed by an enzyme immunoassay (EIA) technique. It was found that at lower doses of arecoline, AN and BL extracts had significantly stimulated testosterone production over the basal level (p < 0.05). BQ extract, on the other hand, did not show any significant effect on testosterone production. Combinations of arecoline at low doses with 10 ng/ml ovine leutinizing hormone (oLH) showed increases in testosterone produced, while cyclic adenosine monophosphate (cAMP) co-culture showed dose-related inhibition. Our current finding hints at the possible dose-dependent dualistic role of AN and BL extracts and arecoline for testosterone production employing possible non-cAMP-dependent pathway of steroidogenesis. However, the identity of the active compounds besides arecoline and the exact mechanism involved remains to be further investigated.

Cotinine inhibits catecholamine release evoked by cholinergic stimulation from the rat adrenal medulla

The aim of the present study was to clarify whether cotinine affects the release of catecholamines (CA) from the isolated perfused rat adrenal gland, and to establish the mechanism of its action, in comparison with the response of nicotine. Cotinine (0.3-3 mM), when perfused into an adrenal vein for 60 min, inhibited CA secretory responses evoked by ACh (5.32 mM), DMPP (a selective neuronal nicotinic agonist, 100 microM for 2 min) and McN-A-343 (a selective muscarinic M1-agonist, 100 microM for 2 min) in dose- and time-dependent manners. However, cotinine did not affect CA secretion by high K+ (56 mM). Cotinine itself also failed to affect basal CA output. Furthermore, in the presence of cotinine (1 mM), CA secretory responses evoked by Bay-K-8644 (an activator of L-type Ca2+ channels, 10 microM) and cyclopiazonic acid (an inhibitor of cytoplasmic Ca2+-ATPase, 10 microM) were relative time-dependently attenuated. However, nicotine (30 microM), given into the adrenal gland for 60 min, initially rather enhanced CA secretory responses evoked by ACh and high K+, followed by the inhibition later, while it time-dependently depressed the CA release evoked by McN-A-343 and DMPP. Taken together, these results suggest that cotinine inhibits greatly CA secretion evoked by stimulation of cholinergic (both nicotinic and muscarinic) receptors, but does fail to affect that by the direct membrane-depolarization. It seems that this inhibitory effect of cotinine may be exerted by the cholinergic blockade, which is associated with blocking both the calcium influx into the rat adrenal medullary chromaffin cells and Ca2+ release from the cytoplasmic calcium store. It also seems that there is a big difference in the mode of action between cotinine and nicotine in the rat adrenomedullary CA secretion.

Endogenous ouabain-like factor (OLF) secretion is modulated by nicotinic mechanisms in rat adrenocortical cells

This study tested the hypothesis that rat adrenocortical secretion of endogenous ouabain-like factor (OLF) is regulated by nicotinic mechanisms. OLF secreted by dispersed cell suspensions of zona glomerulosa (ZG) and fasciculata/reticularis (ZFR) cells was found to co-elute with authentic ouabain by reverse phase HPLC; OLF concentrations in cell supernatants were measured by radioimmunoassay. Nicotine (10(-6) - 10(-3) M) stimulated significant OLF secretion in rat adrenocortical cells. Acetylcholine (10(-7) - 10(-4) M) and eserine (10(-7) - 10(-3) M) stimulated OLF secretion in ZG cells at lower concentrations and stimulated at higher concentrations. Acetylcholine had no effect on ZFR secretion of OLF, but eserine stimulated OLF secretion. ACTH (10(-8) M) strongly potentiated the OLF stimulatory effect of nicotine in ZG cells; however significant interactions between nicotine and ACTH or angiotensin II on OLF secretion in ZFR cells were not apparent. The ganglionic blockers hexamethonium and mecamylamine further potentiated the effect of nicotine, implicating nicotinic acetylcholine receptors (nAChRs) in regulation of OLF secretion. The alpha7-receptor antagonist methyllycaconitine (MLA) dose-dependently inhibited the effect of nicotine in the ZG cells, and in ZFR cells MLA potentiated nicotine-induced OLF secretion. These data suggest that nicotinic regulation may underlie OLF secretion by rat adrenocortical cells, and strongly suggest presence of functional nicotinic acetylcholine receptors on these cells.

Effects of intravenous cocaine and cigarette smoking on luteinizing hormone, testosterone, and prolactin in men

Cocaine and nicotine have a number of similar behavioral and neurobiological effects. This study compared the acute effects of cocaine and cigarette smoking on luteinizing hormone (LH), testosterone (T), and prolactin. Twenty-four men who met American Psychiatric Association Diagnostic and Statistical Manual criteria for cocaine abuse or nicotine dependence were given intravenous cocaine (0.4 mg/kg) or placebo-cocaine, or smoked a low or high nicotine cigarette under controlled conditions. Placebo-cocaine or low nicotine cigarette smoking did not change LH, T, or prolactin. Peak plasma levels of 254 +/- 18 ng cocaine/ml and 22.6 +/- 3.4 ng nicotine/ml were measured at 8 and 14 min, respectively. LH increased significantly after both i.v. cocaine and high nicotine cigarette smoking (P < 0.01). These LH increases were significantly correlated with increases in cocaine and nicotine plasma levels (P < 0.001-0.003), and high nicotine cigarette smoking stimulated significantly greater increases in LH release than i.v. cocaine (P < 0.05). Testosterone levels did not change significantly after either cocaine or after high nicotine cigarette smoking. After i.v. cocaine, prolactin decreased significantly and remained below baseline levels throughout the sampling period (P < 0.05-0.01). After high nicotine cigarette smoking, prolactin increased to hyperpro-lactinemic levels within 6 min and remained significantly above baseline levels for 42 min (P < 0.05-0.03). The rapid increases in LH and reports of subjective "high" after both i.v. cocaine and high nicotine cigarette smoking illustrate the similarities between these drugs and suggest a possible contribution of LH to their abuse-related effects.

Prevention of chronic alcohol and nicotine-induced azospermia, sterility and decreased libido, by a novel tri-substituted benzoflavone moiety from Passiflora incarnata Linneaus in healthy male rats

Excessive long term consumption of alcohol and nicotine have serious detrimental effects upon the libido, fertility, and sperm count in male species. The present work describes the beneficial effects of a novel tri-substituted benzoflavone moiety (BZF) isolated from Passiflora incarnata Linneaus, the phyto-chemical isolation, spectroscopic elucidation, and multifarious biological activities of which have recently been reported by the authors. The BZF moiety has been reported to increase libido, sperm count, and sexual fertility in 2 years old male rats at 10 mg/kg, po dose, in the one of our previous studies. Presently, the BZF moiety has been evaluated against chronic ethanol- and nicotine-induced decrease in libido, sexual fertility and mating efficiency in healthy male rats. The male rats were given ethanol (3 g/kg, po) A, nicotine (2 mg/kg, sc) N, alcohol-nicotine combinations (AN) alone, and also with 10 mg/kg po dose of BZF (concurrent administrations). These treatments were given for 30 days. At the end of treatments, it was observed that rat groups A, N, and AN had no libido (evaluated by mounting behaviour), declined sperm count, and consequently no mating efficiency or fertility (upon pairing with pro-estrus female rats). However, the rats which were given 10 mg/kg BZF along-with nicotine (NP group), alcohol (AP group), and alcohol-nicotine combination (ANP) exhibited significant libido-oriented mounting behaviour, increased sperm count (significantly comparable to the control group), and increased fertilization potential. The rats having decreased sperm count, libido and fertilization potential due to chronic administration of alcohol, nicotine and alcohol-nicotine combinations, i.e., rats of A, N, and AN groups were again subdivided and were given 10 mg/kg BZF for 7 days. This treatment confirmed that BZF speeds up the restoration of sexuality in rats upon cessation of the administration of substances like alcohol, nicotine and alcohol-nicotine combinations, which have severe detrimental effects upon male sexuality, fertility and vigour. BZF, the strongest inhibitor of aromatase enzyme, when administered concurrently with substances like alcohol and nicotine restores sexual virility, libido and vigour in male rats by maintaining the blood-testosterone levels to be high.

Male sexual function and its disorders: physiology, pathophysiology, clinical investigation, and treatment

This review is designed to help the reproductive endocrinologist integrate his or her professional activity with those of other disciplines including urology, radiology, neurology, and psychology in order to successfully manage all of the inseparable aspects of male sexual and reproductive functioning. Significant advances in the field of male sexual physiology and pathophysiology and new methods of investigation and treatment of male sexual disorders are outlined. The review synthesizes available data on the following: norms of sexual organs, aging and sexuality, role of central and peripheral neurochemicals in each stage of the sexual cycle, role of corporeal smooth muscles in the hemodynamic control of erection and detumescence, influence of psychological factors, drugs, and disease on all aspects of sexual functioning, and use of nocturnal penile tumescence monitoring, imaging investigations, and neurophysiologic studies in the diagnostic workup of males with sexual dysfunction. Clinical algorithms are presented where appropriate. Extensive discussions on newly developed strategies in psychological and behavioral counseling, drug therapy, tissue engineering, nonsurgical devices, and surgical treatments for all forms of sexual disorders are also provided. Lastly, the effect of sexual dysfunction and its treatment on quality of life in affected men is addressed, along with recommendations for future research endeavors.

Cigarette smoke and hypoxia induce acute changes in the testicular and cerebral microcirculation

The acute effects of cigarette smoking and hypoxia on the cerebral and testicular microcirculation were studied in anestethised adult rats. Smoking for 2 min did not influence arterial pO2, pCO2 or pH but it induced an increase in cerebral blood flow by 34% and inhibited vasomotion in the testis for about 1 h. One hour after smoke exposure apnea induced a slight increase in arterial pCO2, a significant decrease in pO2, and an increase in cerebral blood flow (CBF) by 54%. In animals not previously exposed to cigarette smoke apnea increased CBF by 121%, demonstrating that a short-term exposure to tobacco smoke influences the cerebrovascular reactivity for more than one hour. In the testis, apnea resulted in a decreased blood flow by 39% and a complete depression of vasomotion. Breathing 10% O2/90% N2 resulted in moderate hypoxia, a total disappearance of the vasomotion in the testis, a 24% decrease in testicular blood flow, but a 23% increase in CBF.

Prenatal effects of maternal smoking on daughters' smoking: nicotine or testosterone exposure?

OBJECTIVES

The purpose of this study was to specify the effect of prenatal fetal exposure to maternal cotinine and testosterone on daughters' smoking in adolescence and adulthood.

METHODS

Longitudinal causal models were estimated among 240 White mother-daughter pairs from the Child Health and Development Study. Mothers and daughters were reinterviewed when daughters were aged 15 to 17 years, and daughters were interviewed at 27 to 30 years of age. Blood samples were obtained from both parents during pregnancy and from adult daughters.

RESULTS

Testosterone and smoking were positively correlated among mothers during their pregnancy and among adult daughters. Maternal prenatal cotinine had no direct effect on daughters' smoking; self-reported smoking in pregnancy did have a direct effect. Smoking among daughters during adolescence was determined by maternal prenatal testosterone and self-reported maternal smoking during pregnancy and postnatally. Smoking among adult daughters reflected chronic smoking since adolescence and the continuing effect of postnatal maternal smoking. Prenatal maternal testosterone affected adult daughters' testosterone.

CONCLUSIONS

Estimates of the impact of prenatal maternal smoking depend on the measure of smoking. Prenatal testosterone exposure is a previously unrecognized risk factor for smoking among female offspring.

Cigarette smoking and erectile dysfunction

Erectile dysfunction (ED, formerly referred to as impotence, is a common (especially in diabetic and older men) and distressing condition. Several risk factors have been identified; among these are smoking, hyperlipidaemia, hypertension and diabetes mellitus. These risk factors are shared with atherosclerotic vascular disease (e.g. ischaemic heart disease). This observation underlies a common vascular pathology. Smoking may cause ED by several mechanisms, including adversely affecting intrapenile blood flow. It is important to be aware of the link between smoking and ED since this information may motivate some male smokers to quit. In this context, it is important to be aware of the link between smoking and ED since this information may motivate smokers to quit. In this context, it is relevant that there is evidence that quitting may restore/improve erectile function.

Comparison of prostate size in university and Veterans Affairs Health Care System patients with negative prostate biopsies

OBJECTIVES

Many important prostate studies take place at Veterans Affairs hospitals. We have examined whether the patient population at these institutions is comparable to the population presenting for prostate evaluation at university hospitals.

METHODS

We included all patients presenting for transrectal ultrasound (TRUS) and biopsy in whom systematic biopsies failed to reveal prostate cancer at both Stanford University Medical Center (90 patients) and the Palo Alto Veterans Affairs Health Care System (103 patients) from August 1, 1995 to July 31, 1996. Identical techniques and equipment for TRUS examination and prostate size determination were used at both institutions.

RESULTS

There was no significant difference in the age or prostate-specific antigen (PSA) levels of the patients at the two institutions. The mean prostatic volume of the Stanford University patients was 71 cm3 (median 63 cm3), whereas the mean prostatic volume of patients at the Palo Alto Veterans Affairs hospital was 52 cm3 (median 43 cm3), a highly statistically significant difference (P = 0.0009).

CONCLUSIONS

The smaller size of the prostate glands in Veterans Affairs patients may be the result of differences in referral base, socioeconomic factors, or environmental factors. These data may have significance for trials conducted only on the prostates of men who are seen at Veterans Affairs hospitals.

Tobacco smoke disrupts testicular microcirculation in the rat

Anaesthetized adult rats were exposed repeatedly to cigarette smoke for 2 s interspersed with exposure to fresh air for either 10, 15 or 30 s using a smoking apparatus. The acute effects of this treatment on testicular microcirculation were studied using laser Doppler flowmetry. Peripheral tissue O2 saturation was measured continuously in the foot during the experiment. Exposure to cigarette smoke caused a moderate acute increase in the testicular blood flow and it inhibited vasomotion. Blood flow and the pattern of vasomotion were normalized after termination of smoke exposure. The time between the last smoke exposure and flow normalization was dependent on the smoke/air dose. Peripheral tissue O2 saturation did not change during the experiments. The effects on testicular microcirculation of local injections of an aqueous extract of cigarette smoke and passive smoking were also studied. Local injection of smoke extract increased blood flow and inhibited vasomotion. Passive smoking caused a moderate decrease in the frequency of vasomotion and amplitude. The observation that cigarette smoke influences testicular microcirculation acutely is discussed in relation to possible adverse effects on spermatogenesis.

Relationship of smoking cessation and nicotine gum use to salivary androstenedione and testosterone in middle-aged men

Cross-sectional studies have associated cigarette smoking in men with elevated androstenedione and little net effect on other sex steroids. However, it is not clear if such findings reflect the impact of nicotine exposure or if sex hormone levels change following smoking cessation. The relationship of the reported number of cigarettes smoked per day and salivary cotinine to salivary testosterone and androstenedione was examined in 221 men aged 35 to 59 years at baseline and 1 year following randomization into a clinical trial including a smoking-cessation intervention. At baseline, salivary cotinine was related to increased salivary androstenedione and testosterone following control for age, body mass, alcohol intake, and time of day of specimen collection (partial r = +.14 and +.30 P < .05 and .01, respectively). The reported number of cigarettes smoked per day was unrelated to either hormone. At the first annual visit, there was a significant decrease in the salivary androstenedione of men who had quite smoking and were currently using nicotine gum (94 v 60 pg/mL, P < .05, n = 34) and of men who had quit smoking and were not exposed to nicotine (86 v 56 pg/mL, P < .05, n = 48), whereas the salivary androstenedione of men who remained smokers at the first annual visit was unchanged (83 v 85 pg/mL, n = 139). Salivary testosterone levels were not significantly affected by a change in smoking status.(ABSTRACT TRUNCATED AT 250 WORDS)

Exposure to environmental tobacco smoke increases myocardial infarct size in rats

BACKGROUND

Exposure to environmental tobacco smoke (ETS) has been epidemiologically linked to death from ischemic heart disease in nonsmokers. In this study, we evaluated the influence of 3 days, 3 weeks, and 6 weeks of ETS exposure on myocardial infarct size in a rat ischemia/reperfusion model.

METHODS AND RESULTS

Sprague-Dawley rats exposed to ETS (four Marlboro cigarettes per 15 minutes, 6 hours per day, 5 days per week) for 3 days (n = 24), 3 weeks (n = 21), or 6 weeks (n = 12) and control rats (n = 24, n = 21, and n = 12, respectively) were subjected to 35 minutes of left coronary artery occlusion and 2 hours of reperfusion. Infarct size and risk area were determined by triphenyltetrazolium chloride and phthalocyanine blue staining, respectively. Air nicotine, carbon monoxide, and total particulates were measured during ETS exposure. Serum lipids, plasma carbon monoxide hemoglobin (COHb), nicotine, and cotinine concentrations were measured in additional groups (6 to 13 rats each) exposed to 3 days, 3 weeks, or 6 weeks of ETS and controls. Average air nicotine, carbon monoxide, and total particulate concentrations were 1103 micrograms/m3, 92 ppm, and 60 mg/m3 for the ETS-exposed rats. Infarct size (infarct mass/risk area x 100%) increased significantly in the ETS groups compared with the control groups in a dose-dependent manner (P = .023), with longer exposure associated with larger infarct size. Infarct size nearly doubled with 6 weeks of ETS exposure (61 +/- 5% versus 34 +/- 3% for control, mean +/- SEM). Plasma COHb, nicotine, and cotinine levels increased significantly in the ETS groups in a dose-dependent manner (all P < .001).

CONCLUSIONS

Exposure to passive smoking increases myocardial infarct size in a rat model of ischemia and reperfusion. This increase of infarct size exhibited a dose-response relation. These results are consistent with epidemiological studies demonstrating that ETS increases the risk of heart death.

Does early exposure to maternal smoking affect future fertility in adult males?

Animal data suggest that prenatal exposure to certain tobacco smoke components such as nicotine may affect the development of the male gonadal axis, which may in turn affect future adult fertility. There are no previous epidemiologic studies on the potential effects of early (prenatal and childhood) exposure to maternal smoking on the reproductive system in adult male offspring. To investigate this question, we used data from a follow-up study of reproductive function and fertility among young adult sons of mothers who had participated in a randomized clinical trial of diethylstilbestrol use during pregnancy. We observed no significant effects of early exposure to maternal smoking on conventional semen characteristics, hormone levels (follicle stimulating hormone [FSH], luteinizing hormone [LH] and testosterone), urogenital abnormalities and diseases, or perceived infertility problems. Current active smoking by the men was, however, associated with a significant decrease in the percentage of sperm with normal morphology.