Piacsek B E, Statham N J, Goodspeed M P
Am J Physiol. 1978 Mar;234(3):E262-6. doi: 10.1152/ajpendo.1978.234.3.E262.
Male rats were raised from birth in either continuous light (LL) or in 14 h light/10 h dark per day (LD) at 22 +/- 1 degree C. Food and water were administered ad libitum. Groups of rats were killed by decapitation at 14, 20, 25, 35, 41, 45, 51, 55, 58, 63, and 79 days of age. Testicular (TW), ventral prostate (VPW), and seminal vesicle (SVW) weights were measured. Serum concentrations of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), and androgens were quantified by radioimmunoassay. Results indicate no significant change in TW or spermatogenesis. Spermatozoa were first seen in the lumen of 10% of seminiferous tubules at 35 days of age in both LD and LL rats and by 42 days of age, 80% of tubules from both LD and LL rats contained spermatozoa in the lumen. A highly significant depression in accessory structure development (VPW, SVW) was observed as a result of LL exposure. Serum FSH levels in LL rats were depressed on days 45, 51, 55, and 58 but elevated at 79. Serum PRL concentrations were elevated in LL rats on days 41, 55, 58, 63, and 79, whereas serum androgen levels were depressed on days 58, 63, and 79. Results suggest that exposure to LL results in delayed maturation of the accessory structures in the reproductive system of the male rat possibly as a result of reduced FSH or elevated PRL levels, which in turn may modify the rate and pattern of LH and/or androgen secretion.
雄性大鼠从出生起饲养在22±1摄氏度的环境中，光照条件分为持续光照（LL）或每天14小时光照/10小时黑暗（LD）。食物和水随意供应。在大鼠14、20、25、35、41、45、51、55、58、63和79日龄时，通过断头法处死大鼠分组。测量睾丸（TW）、腹侧前列腺（VPW）和精囊（SVW）的重量。通过放射免疫测定法定量血清中促卵泡激素（FSH）、促黄体生成素（LH）、催乳素（PRL）和雄激素的浓度。结果表明睾丸重量或精子发生没有显著变化。在LD和LL大鼠中，35日龄时在10%的生精小管腔中首次见到精子，到42日龄时，LD和LL大鼠的80%的小管腔中都含有精子。观察到持续光照暴露导致附属结构发育（VPW、SVW）出现高度显著的抑制。LL大鼠在45、51、55和58日龄时血清FSH水平降低，但在79日龄时升高。LL大鼠在41、55、58、63和79日龄时血清PRL浓度升高，而在58、63和79日龄时血清雄激素水平降低。结果表明，持续光照暴露可能导致雄性大鼠生殖系统附属结构成熟延迟，这可能是由于FSH降低或PRL水平升高，进而可能改变LH和/或雄激素分泌的速率和模式。
