Steger R W, Bartke A, Matt K S, Soares M J, Talamantes F
J Exp Zool. 1984 Mar;229(3):467-74. doi: 10.1002/jez.1402290314.
Transfer of gonadally regressed male golden hamsters from a short (5 L:19 D) to a stimulatory (14 L:10 D) photoperiod elicits, within 24 hr, significant changes in hypothalamic dopamine, serotonin, and possibly norepinephrine metabolism. Hypothalamic LHRH content was significantly elevated in short-photoperiod animals, but within 24 hr of transfer to a 14:10 photoperiod, LHRH declined to levels not different from those in hamsters maintained continuously in a long photoperiod. Plasma FSH levels were also significantly elevated within 24 hr of transfer, but increases in plasma LH were somewhat slower. Chronic treatment with the tyrosine hydroxylase inhibitor, alpha-methyl tyrosine (alpha MPT), which inhibits catecholamine synthesis, blocked the effect of a stimulatory photoperiod on plasma FSH levels, while treatment of 5:19 hamsters with the catecholamine precursor, L-dopa, mimicked the effects of photostimulation on plasma FSH levels. Testicular weights were not affected by alpha MPT or L-dopa treatment for 1 week. From these data, it appears that endocrine events associated with photoperiod-induced testicular recrudescence are under the control of hypothalamic neurotransmitters.
将性腺退化的雄性金黄仓鼠从短光照周期（5小时光照：19小时黑暗）转移到刺激性光照周期（14小时光照：10小时黑暗），会在24小时内引起下丘脑多巴胺、血清素以及可能的去甲肾上腺素代谢的显著变化。短光照周期动物的下丘脑促性腺激素释放激素（LHRH）含量显著升高，但在转移到14:10光照周期的24小时内，LHRH下降到与长期处于长光照周期的仓鼠无异的水平。血浆促卵泡激素（FSH）水平在转移后的24小时内也显著升高，但血浆促黄体生成素（LH）的升高则稍慢一些。用酪氨酸羟化酶抑制剂α-甲基酪氨酸（αMPT）进行慢性治疗，该抑制剂可抑制儿茶酚胺合成，阻断了刺激性光照周期对血浆FSH水平的影响，而用儿茶酚胺前体L-多巴治疗处于5:19光照周期的仓鼠，则模拟了光刺激对血浆FSH水平的影响。睾丸重量在1周的αMPT或L-多巴治疗下未受影响。从这些数据来看，与光周期诱导的睾丸再发育相关的内分泌事件受下丘脑神经递质的控制。
