Connexin 32 mRNA levels in the rat supraoptic nucleus: up-regulation prior to parturition and during lactation.
Connexin 32 mRNA levels in the rat supraoptic nucleus: up-regulation prior to parturition and during lactation.
复制标题
大鼠视上核中的连接蛋白 32 mRNA 水平：分娩前和哺乳期间上调。
DOI：
10.1159/000126933
复制
发表时间：
1996
影响因子：
4.1
通讯作者：
Hatton,GI
中科院分区：
文献类型：
--
作者：
Micevych,PE;Popper,P;Hatton,GI
在怀孕接近尾声时，哺乳动物的母亲会经历一系列的激素、神经和躯体事件，最终导致分娩和哺乳。排乳是哺乳的最后一步，由下丘脑大细胞核中催产素能神经元的高频同步放电调节。这种神经活动的同步化可能是通过连接蛋白增加大细胞神经元的细胞间耦合来调节的。神经元之间的直接细胞间通道是由连接蛋白32蛋白形成的。本研究用连接蛋白32和连接蛋白43互补的cRNA探针，用半定量原位杂交组织化学方法检测了神经元/少突胶质细胞和星形胶质细胞中连接蛋白32和连接蛋白43的表达模式。缝隙连接蛋白32mRNA在处女视上核中的表达相对较低，在妊娠晚期显著上调。出生后，缝隙连接蛋白32mRNA水平立即下降，与处女的水平相似。在哺乳第13天，当大细胞神经元之间的染料偶联程度很高时，连接蛋白32的信息水平再次非常高。在哺乳期和处女期动物中，星形细胞连接蛋白43的水平没有差别。这些结果表明，间隙连接蛋白32的表达有两个高峰，一个在分娩前，另一个在哺乳期。到目前为止，只有连接蛋白32的第二个峰与视上核大细胞神经元的染料偶联增加有关，这表明在这种情况下，连接蛋白32的信息水平的提高导致了随后的细胞间耦合的增加。
Toward the end of pregnancy, mammalian mothers undergo a cascade of hormonal, neural and somatic events that culminate in birth and lactation. Milk ejection, the final step in lactation, is regulated by high-frequency, synchronized firing of oxytocinergic neurons in the magnocellular nuclei of the hypothalamus. This synchronization of neural activity may be regulated by an increase in the cell-to-cell coupling of magnocellular neurons by connexins. Direct intercellular channels between neurons are formed by the connexin 32 protein. The present study examined the pattern of connexin 32 mRNA levels using semiquantitative in situ hybridization histochemistry with isotopically labeled cRNA probes complementary to connexin 32 and connexin 43, found in neurons/oligodendrocytes and astrocytes, respectively. Connexin 32 mRNA levels were relatively low in the supraoptic nucleus of virgin females and were dramatically up-regulated during late pregnancy. Immediately after birth, connexin 32 mRNA levels dropped and were similar to levels in virgins. On the 13th day of lactation when dye-coupling between magnocellular neurons is high, connexin 32 message levels were again very high. Levels of the astrocytic connexin 43 were no different in lactating and virgin animals. These results demonstrate that there are two peaks of connexin 32 expression, one immediately preceding parturition and one during lactation. So far, only the second peak of connexin 32 is known to be related to an increase in dye-coupling of magnocellular neurons in the supraoptic nucleus, suggesting that in this case, the elevation of connexin 32 message levels leads to the subsequent increase in intercellular coupling.