Serum leptin correlates in infertile oligozoospermic males.

Leptin is an adipocyte-secreted protein that participates in the regulation of energy homeostasis. Eighty men were investigated; fertile normozoospermia as a control (n = 30) and infertile oligozoospermia (n = 50). The patients underwent estimation of body weight (kg), height (cm), calculation of body mass index (BMI), semen analysis, serum leptin and testosterone hormones. Mean body weight was significantly higher in infertile oligozoospermia compared with controls. Mean height, BMI and serum testosterone levels showed nonsignificant differences between the two groups. Infertile oligozoospermia had significantly higher mean serum leptin level than controls (mean +/- SD; 6.88 +/- 8.65, 16.3 +/- 13.98 ng ml(-1), P < 0.01). Serum leptin demonstrated significant positive correlation with age, body weight, BMI and significant inverse correlation with serum testosterone. It had nonsignificant correlation with the height and sperm concentration. These results are suggestive of a link between the adipocyte derived hormone, leptin and male reproduction.

Role of zinc in regulating the testicular function. Part 2. Effect of dietary zinc deficiency on gonadotropins, prolactin and testosterone levels as well as 3 beta-hydroxysteroid dehydrogenase activity in testes of male albino rats.

Induced zinc deficiency in male albino rats caused a great reduction in the testicular levels of testosterone as compared to control and zinc-supplemented (ZS) rats. Estimation of the testicular levels of follicle-stimulating hormone, luteinizing hormone and prolactin (PRL) in the zinc-deficient (ZD) rats showed higher levels in comparison with both control and zinc-supplemented rats. However, the increase in PRL levels was statistically insignificant. A great reduction in the activity of 3 beta-hydroxysteroid dehydrogenase, an important enzyme involved in testosterone biosynthesis, was demonstrated histochemically in the testes of ZD rats as compared to both control and ZS ones. These results reflect a direct action of zinc deficiency on the testicular steroidogenesis and strongly support the idea that the hypogonadal state associated with zinc deficiency results mainly from some alteration in the testicular steroidogenesis or in other words Leydig cell failure.

Cigarette smoking and male reproduction.

The effects of cigarette smoking on male reproduction were studied through measuring the serum estradiol (E2), prolactin (PRL), and total testosterone (T). Smoking men had higher levels of E2 and PRL but normal T compared to nonsmokers. Raised E2 and PRL may be among the mechanisms through which cigarette smoking impairs male reproduction.

PIP: Male cigarette smokers have been found to have a lower proportion of motile sperm than nonsmokers, and some studies have reported an increased proportion of abnormal sperm in smokers. To further assess the effects of cigarette smoking on male reproduction, serum levels of estradiol (E2), prolactin (PRL), and total testosterone (T) were compared in 50 heavy smokers (median 23.5 cigarettes/day) and 35 men who never smoked. The median age was 25.4 years among smokers and 27.4 years among nonsmokers. The differences between these 2 groups of men in terms of E2 and PRL levels were significant. Smokers showed elevated E2 levels (median, 59.8 pcg/ml + or - 1.83) compared with nonsmokers (median, 48.6 pcg/ml + or - 0.9) (p 0.001). The median serum PRL level was 10.11 ng/ml + or - 0.55 in smokers compared with 7.88 ng/ml = or - 0.54 in nonsmokers (p 0.001). The median level of serum T did not differ significantly between smokers (4.53 ng/ml + or - 0.17) and nonsmokers (4.55 ng/ml + or - 0.24). Of interest is the finding that smoking appears to elevate E2 in men, while it lowers E2 in women. Since estrogen is a strong stimulus for PRL secretion, the elevated E2 level in smokers may be the mechanism that produces raised serum PRL as well. The finding of a lack of difference between smokers and nonsmokers in T levels suggests that the steroidogenic function of the testis is not affected by smoking; on the other hand, smoking may affect the free fraction of T.