成年大鼠神经垂体垂体细胞超微结构观察

ULTRASTRUCTURAL OBSERVATION OF PITUICYTES IN NEUROHYPOPHYSIS OF ADULT RATS

本研究在电镜下对6只成年雄性大白鼠的神经垂体进行观察,以了解垂体细胞的形态学特点及其功能意义。垂体细胞可分为4型,其中星形垂体细胞和室管膜垂体细胞的形态特征,与中枢神经系统的神经胶质细胞相似。暗垂体细胞富含线粒体,其功能尚难评价。分泌型垂体细胞的胞浆中有分泌颗粒存在,提示该型细胞可能具有分泌功能。细胞间池是神经膨大进行分泌活动的场所,其周围有较多富于小泡的神经膨大。形态学证据说明,垂体细胞具有支持、营养和清除坏死物的功能。此外,由于垂体细胞之间缝隙连接及垂体细胞与神经膨大之间突触样连接的存在,表明该细胞还可能具有传递兴奋的作用。

Neurohypophyses of six adult rats were observed under electron microscope to investigate the morphological features of pituicytes and their possible functional significance.The results of morphological observation showed that the pituicytes may be divided into 4 types,the two of which,astral pituicytes and ependymal pituicytes,obviously resemble to the neurogliocytes of central nervous system in their morphological features.The third,dark pituicytes,was rich in mitochondria. Little was known about secretory pituicytes other than their presumable secretory function suggested by the secretory granules present in their cytoplasm. The interstitial cisternae were the sites where the neurosecretory activities carried on.The dilations of nerve fiber around the interstitial cisternae were rich in vesi- cles. It was substantiated that the pituicytes can participate in supporting and nourishing the nerve fibers,removing cell debris and may also serve a function of transferring excitation,because of the presence of gap junction between pituicytes and ynapselike contact between pituicyte and the nerve fiber.