Diurnal expression of Fos in luteinizing hormone-releasing hormone neurons of Syrian hamsters.
Diurnal expression of Fos in luteinizing hormone-releasing hormone neurons of Syrian hamsters.
复制标题
叙利亚仓鼠黄体生成素释放激素神经元中 Fos 的昼夜表达。
DOI：
10.1095/biolreprod50.2.301
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发表时间：
1994
影响因子：
3.6
通讯作者：
Urbanski,HF
中科院分区：
文献类型：
--
作者：
Doan,A;Urbanski,HF
本研究的目的有两个方面：首先，研究发情仓鼠LHRH神经元表达增加与血浆LH、FSH、雌二醇-17β (E2)和孕酮水平升高之间的时间关系（P4）；第二，确定雄性仓鼠是否和雌性仓鼠一样，在表达fos的LHRH神经元数量上也表现出昼夜变化。分别于0900、1200h、1500h、1800h和0300、0900h、1500h、2100 h采集雌鼠的血液样本。血浆RIA显示，雌鼠的LH、FSH、e2在1500 h达到峰值，p4在1800 h达到峰值；在1500 h时，雄性LH也出现了一个显著但较小的峰值。双标记免疫细胞化学，使用针对人类fosin蛋白127-152氨基酸和LHRH的抗体，显示雌性仓鼠在发情前的上午和中午表达fosin少于LHRH神经元的10%，但在下午晚些时候（1800小时），这些神经元的表达率约为41%。相比之下，雄性仓鼠的LHRH神经元在一天中的任何时间都没有表达。在排卵前促性腺激素激增开始后，雌性小鼠的LHRH神经元数量增加，而不是在排卵前促性腺激素激增开始之前，这一发现意义重大，因为它不容易支持直接早期基因的表达在某种程度上与诱导激增有关的假设。相反，结果与以下观点一致，即fosin LHRH神经元的表达要么反映了负责终止激增的机制的激活，要么反映了负责补充耗尽神经肽储备的补偿机制的激活。
The aim of the present study was two-fold: first, to examine the temporal relationship between increased expression ofFosin LHRH neurons of proestrous hamsters and increased plasma levels of LH, FSH, estradiol-17β (E2), and progesterone (P4); and second, to establish whether male hamsters, like females, also show diurnal variations in the number of LHRH neurons expressingFos. Blood samples were collected from proestrous females at 0900 n, 1200 h, 1500 h, and 1800 h and also from males at 0300 h, 0900 h, 1500 h, and 2100 h. RIA of the plasma revealed significant peaks of LH, FSH, and E2at 1500 h, and of P4at 1800 h in the females; a significant but smaller peak of LH also occurred at 1500 h in the males. Double-label immunocytochemistry, using antibodies directed against amino acids 127–152 of the humanFosprotein and against LHRH, showed that female hamsters expressedFosin fewer than 10% of their LHRH neurons during the morning and at noon of proestrus but in approximately 41% of these neurons during the late afternoon (1800 h). In contrast, no expression ofFosoccurred in LHRH neurons of male hamsters at any time of the day. The finding that the females showed an increase in the number of LHRH neurons expressingFosafter, and not before, the initiation of the preovulatory gonadotropin surge is significant because it does not readily support the hypothesis that this expression of immediate-early genes is in some way associated with the induction of the surge. Instead, the results are consistent with the view that expression ofFosin LHRH neurons reflects either the activation of a mechanism responsible for terminating the surge or, alternatively, the activation of a compensatory mechanism responsible for replenishing depleted neuropeptide stocks.