Shaw D, Goldman B D
Department of Physiology and Neurobiology, University of Connecticut, Storrs 06269-4154, USA.
Endocrinology. 1995 Oct;136(10):4231-6. doi: 10.1210/endo.136.10.7664640.
Prepubertal reproductive development in juvenile male Siberian hamsters can be strongly influenced by photoperiod information received during gestation. Information transmitted from the mother hamster to her fetuses appears to modify the photoperiodic mechanism of the developing hamsters so that they may respond differently to certain intermediate day lengths [i.e. 14 h of light and 10 h of darkness/day (14L)] experienced after birth depending on whether gestation occurred in longer or shorter day lengths. In adult and juvenile hamsters, the duration of the nocturnal elevation of pineal and serum melatonin (MEL) is an important component of the photoperiodic system coding for day length. In the present study, we investigated whether the photoperiod in effect during gestation could influence the responsiveness of developing male hamsters to daily MEL infusions of fixed durations administered after weaning. The results indicated that hamsters gestated under 16L or 10L did not differ from each other with respect to testicular growth in response to any of the fixed duration MEL infusions. Thus, target tissue responsiveness to fixed duration MEL infusions (over a range of 6-10 h) was the same regardless of the gestation photoperiod to which the animals had been exposed.
幼年雄性西伯利亚仓鼠青春期前的生殖发育会受到孕期所接收的光周期信息的强烈影响。从母仓鼠传递给其胎儿的信息似乎会改变发育中仓鼠的光周期机制，这样它们出生后对于特定中间光周期（即每天14小时光照和10小时黑暗 [14L]）的反应可能会有所不同，这取决于孕期是处于较长还是较短的光周期。在成年和幼年仓鼠中，松果体和血清褪黑素（MEL）夜间升高的持续时间是光周期系统中编码日长的一个重要组成部分。在本研究中，我们调查了孕期的光周期是否会影响发育中的雄性仓鼠对断奶后给予的固定时长每日MEL注射的反应。结果表明，在16L或10L光照条件下受孕的仓鼠，对任何固定时长的MEL注射的睾丸生长反应并无差异。因此，无论动物所经历的孕期光周期如何，靶组织对固定时长（6 - 10小时范围内）MEL注射的反应都是相同的。
