中老年可男性睾酮部分缺乏症.ppt

* * 前面讲到，睾酮是由睾丸间质细胞分泌的。在中老年男性，随着年龄的增加，间质细胞数量是逐步减少的。 Reference Neaves WB, Johnson L, Porter JC, Parker CR, Petty CS. Leydig cell numbers, daily sperm production, and serum gonadotropin levels in aging men. J Clin Endocrinol Metab 1984;55:756-763 * * Historically,it has been always recognized that androgens play in maintaining sexual activity was thought to be via it role mainly on sexual interest. But with accumulating evidence both animals and humans to androgen’s local effects: Animal studies showed that expression of nitric oxide synthase (NOS) gene inside the penis depends on the presence of adequate androgen levels (Penson et al. 1996, Mills Lewis 1999; mills et al. 1999) Castration may also affect PDE5 gene expression (Traish et al. 1999) In humans, it has been observed that the efficacy of erectile dysfunction (ED) therapy with PDE5 inhibitors (PDE5i) may be blunted in patients with subclinical hypogonadism in whom androgen levels have not been previously normalized (Guay et al. 2001) In general, evidence indicate that testosterone is involved in the maintenance of sexual activity at multiple sites (Anderson et al. 1992) and that adequate blood testosterone concentration are necessary to keep intact molecular machinery of penile erection (Rakic et al. 1997) * * NOTES Aging men, similar to aging women, do undergo a variety of hormonal changes, including decreasing serum testosterone levels. In the longitudinal analysis of the Massachusetts Male Aging Study, a total of 1,156 men between the ages of 40 and 70 years at entry were followed for 7-10 years. There were age-related increases of FSH, LH, SHBG and prolactin. On the other hand, age-related decreases were found for total, free and albumin-bound testosterone, DHEA, DHEA-S, estrone and cortisol. The effects of the longitudinal study were more pronounced than those of a the previously published cross-sectional analysis of the same study. According to the authors, this may reflect that incident poor health m