Morphological adaptability at neurosecretory axonal endings on the neurovascular contact zone of the rat neurohypophysis
Morphological adaptability at neurosecretory axonal endings on the neurovascular contact zone of the rat neurohypophysis
复制标题
大鼠神经垂体神经血管接触区神经分泌轴突末端的形态适应性
DOI：
10.1016/0306-4522(87)90016-9
复制
发表时间：
1987
期刊：
影响因子：
3.3
通讯作者：
Glenn I. Hatton
中科院分区：
文献类型：
--
作者：
C. Tweedle;Glenn I. Hatton
为了比较引起或终止激素释放的各种急性和慢性刺激的作用，在以下处理组的年轻成年大鼠中定量检查了神经垂体神经血管接触区基底层处神经末梢接触的超微结构：未给药处女雌性，未给药雄性大鼠，直肠（妊娠第21天），产后（分娩当天），哺乳期（哺乳14天），幼鼠断奶后10天的母鼠，48 h禁水雄性，给予2%生理盐水的雄性（脱水）10天，雄性动物按所述给予2%盐水，然后给予自来水再水合2或5周。电子显微照片的形态分析表明，所有刺激导致激素释放增加的同时，神经末梢以及减少外壳的神经分泌过程的垂体细胞质的基底层的占领增加。神经占领的基底层仍然显着升高断奶后10天，并在2周（但不是5周）的复水后10天的脱水。在断奶后和5周（但不是2周）再水化的动物中，神经分泌轴突的垂体细胞外壳已恢复到对照值。个别神经末梢与基底层接触的平均长度被发现增加下的一些，但不是所有的，与激素释放增加（即分娩，急性和慢性脱水，但不是在哺乳期），并降低到低于控制值在哺乳期女性和5周后的补液。相反，在哺乳期，这些数据进一步证明，在生理条件下，神经垂体神经终末在基底层的接触以及垂体细胞与神经分泌过程的关系可以以一种方式改变，可能在功能上与控制激素释放的接触面积有关。
To compare the effects of a variety of acute and chronic stimuli that bring about or terminate hormone release the ultrastructure of nerve terminal contact at the basal lamina of the neurohypophysial neurovascular contact zone was examined quantitatively in young adult rats of the following treatment groups: untreated virgin females, untreated male rats, prepartum (day 21 of gestation), postpartum (on the day of parturition), lactating (14 days of suckling), mothers 10 days after their pups were weaned, 48 h water-deprived males, males given 2% saline solution (dehydrated) for 10 days, males given 2% saline as described then given tap water to rehydrate for 2 or 5 weeks. Morphometric analysis of electron micrographs revealed that all stimuli leading to increased hormone release were accompanied by both increased occupation of the basal lamina by nerve terminals as well as decreased enclosure of neurosecretory processes by pituicyte cytoplasm. Neural occupation of the basal lamina remained significantly elevated 10 days post-weaning and at 2 weeks (but not 5 weeks) of rehydration following 10 days of dehydration. Pituicyte enclosure of neurosecretory axons had returned to control values in the postweaning and 5 week (but not 2 week) rehydrated animals. The mean length of individual nerve terminal contact with the basal lamina was found to increase under some, but not all, conditions associated with increased hormone release (i.e. parturition, acute and chronic dehydration, but not during lactation) and to decrease below control values in prepartum females and after 5 weeks of rehydration. During lactation, in contrast, the greater neural coverage of the basal lamina was accompanied by an increased number of terminals per unit length of basal lamina without an increase in the average contact length of the individual terminal.These data provide further evidence that neurohypophysial nerve terminal contact at the basal lamina and the relationship of pituicytes to neurosecretory processes can change under physiological conditions in a manner that is probably functionally related to controlling the contact area for hormone release.