大鼠视上核神经分泌细胞的衰老形态变化

本文选用青年(3个月)、成年(10—12个月)和老年(28—30个月)雄性Wistar大鼠,对其下丘脑视上核神经分泌细胞分别作了光镜和电镜观察与测定。结果表明:老年大鼠视上核前部的神经分泌细胞密度与细胞核体积明显低于青年和成年大鼠,提示老年大鼠视上核有神经元消失和细胞活性降低的表现;神经分泌细胞核周质内的醛复红阳性颗粒未测出三个年龄组大鼠间的差异,含醛复红阳性颗粒的胞突在老年时却显示增粗和膨大;老年动物神经分泌细胞超微结构的主要变化为神经分泌颗粒和脂褐素增加,尤以后者为甚。老年大鼠少数神经分泌细胞还表现有粗面内质网和核蛋白体减少,排列紊乱,池囊扩张和脱颗粒,高尔基复合体池囊变窄或扩张,胞质和胞突内有自噬体样物质出现等衰老改变;多数细胞胞质内的其他结构同青年和成年大鼠者相似。此外。老年大鼠视上核神经毡结构中有多层膜包绕胞突,终末和突触等的鞘样结构出现增多。本研究表明大鼠衰老时视上核神经分泌细胞活性降低。

THE AGING CHANGES OF THE NEUROSECRETORY CELLS IN THE SUPRAOPTIC NUCLEUS OF THE RAT

The neurosecretory cells of the supraoptic nucleus SON of young (3 month), adult(10-12 months) and old (28-30 months) male Wistar rats were studied with light and electron microscope. The main results were as following: In old rats, the neuronal density and cell nuclear volumes revealed significance decrease in rostral part of SON, which suggested that there are neuron loss and decrease of cell activity in SON. The stainability of positive-aldehydefuchsin granules in the neuronal perikaryon appeared similar in three age groups. But the cell processes containing positive-aldehydefuchsin granules became thick and swollen in old rats. No marked differences of ultrastructure in most cells and subcellular components of SON could be detected among three age groups. However, the neurosecrotory granules. and lipofuscins were increased in aged animals, and a few of neurosecretory cells in old rats showed that rough endoplamsic reticula, ribosomes and Golgi complexes were reduced in number and their shepes and arrangement were out of order. In addition, particular membranous sheath structures enclosing axons or nerve endings were frequently found in old rats. The morphological changes of neurosecretory cells might be refered to some functional declines in SON with aging.