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

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.