Jarrige J F, Laurichesse H, Boucher D
Laboratoire de Physiologie Faculté de Médecine, Clermont-Ferrand, France.
Biol Reprod. 1992 Mar;46(3):386-91. doi: 10.1095/biolreprod46.3.386.
Female Sprague-Dawley rats, exposed to a long (18L:6D) or a short (6L:18D) photoperiod from 21 days of age, were mated when they reached 55 days of age. On Day 2 of gestation, dams were pinealectomized or sham-operated. Pre- and postnatal photoperiods were identical, and offspring were killed at 15 days of age. Maternal pinealectomy had no effect when rats were kept on 18L:6D. Rats born to sham-operated mothers and kept on 6L:18D had higher testicular testosterone and androstenedione content than offspring raised on the long photoperiod. This stimulatory effect of the short photoperiod was blocked by maternal pinealectomy and was not dependent on the offspring's own pineal since it was observed in both sham-operated and neonatally (on Day 5 after birth) pinealectomized rats. When sham-operated mothers housed on 18L:6D were treated daily during pregnancy and lactation by s.c. melatonin injection, there was an increase in the testicular testosterone content of offspring. It was concluded that when rats are maintained on a 6L:18D cycle the maternal pineal gland enhances the testicular testosterone and androstenedione content in 15-day-old offspring. This effect is probably mediated by maternally derived melatonin. At 15 days of age, the pineal of the offspring had no influence on testicular function.
从21日龄开始，将雌性斯普拉格-道利大鼠暴露于长光照周期（18小时光照：6小时黑暗）或短光照周期（6小时光照：18小时黑暗）下，55日龄时进行交配。在妊娠第2天，对母鼠进行松果体切除或假手术。产前和产后的光照周期相同，子代在15日龄时处死。当大鼠处于18小时光照：6小时黑暗的光照周期时，母体松果体切除没有影响。假手术母鼠所生且处于6小时光照：18小时黑暗光照周期下的子代，其睾丸睾酮和雄烯二酮含量高于在长光照周期下饲养的子代。短光照周期的这种刺激作用被母体松果体切除所阻断，且不依赖于子代自身的松果体，因为在假手术和新生期（出生后第5天）松果体切除的大鼠中均观察到了这种现象。当处于18小时光照：6小时黑暗光照周期下的假手术母鼠在妊娠和哺乳期每天皮下注射褪黑素时，子代睾丸睾酮含量增加。得出的结论是，当大鼠处于6小时光照：18小时黑暗的周期时，母体松果体可提高15日龄子代睾丸中的睾酮和雄烯二酮含量。这种作用可能是由母体来源的褪黑素介导的。在15日龄时，子代的松果体对睾丸功能没有影响。
