Stepanova M G
Laboratory of Perinatal Biochemistry, D. M. Ott Institute of Obstetrics and Gynecology, Russian Academy of Medical Sciences, Saint Petersburg.
Neurosci Behav Physiol. 1995 Sep-Oct;25(5):357-60. doi: 10.1007/BF02359591.
There are no regular patterns in the fluctuations of the content of gonadoliberin in relation to the time of day in the preoptic region and the median eminence in females and males. However, the existence of a well-marked circadian rhythm of the fluctuations of this neurohormone has been identified in females in the vascular organ of the lamina terminalis. Its level is extremely low in the morning; its level increases five-fold immediately after noon, and ten-fold at 1700-1800 h. This rhythm does not depend on the stage of the estrous cycle and is manifested identically both in diestrus and in proestrus. Circadian fluctuations in the content of gonadoliberin in the vascular organ of the lamina terminalis were not observed in males. The chronic exposure to various xenobiotics in low concentrations (toloul, benzol, dioxan, styrol, and lead) leads to a break in the circadian rhythm of the gonadoliberin content in the vascular organ of the lamina terminalis in females; this is expressed first and foremost in a significant increase in the level of this neurohormone in the morning hours. This is apparently associated with attenuation of inhibitory tone; this is indirectly confirmed by a simultaneous increase in the level of prolactin in the blood.
在雌性和雄性动物的视前区和正中隆起中，促性腺激素释放激素的含量波动与一天中的时间没有规律可循。然而，在雌性动物的终板血管器中，已确定这种神经激素的波动存在明显的昼夜节律。其水平在早晨极低；中午过后立即增加五倍，在1700 - 1800时增加十倍。这种节律不依赖于发情周期阶段，在间情期和发情前期表现相同。在雄性动物的终板血管器中未观察到促性腺激素释放激素含量的昼夜波动。长期低浓度接触各种外源性物质（甲苯、苯、二恶烷、苯乙烯和铅）会导致雌性动物终板血管器中促性腺激素释放激素含量的昼夜节律紊乱；这首先表现为该神经激素在早晨时段的水平显著升高。这显然与抑制性张力减弱有关；血液中催乳素水平同时升高间接证实了这一点。
