RESUMO
Our experiments were designed to observe the cytological changes of the anterior lobes in rats pituitary at electron microscopic level after electric pain-stimulation. obvious changes were founded in the ACTH, GH and PRL cells and slight changes in the FSH and TSH cells. However, the LH cells remained to resemble the normal cells. In the experiment group of the somatic painful stimulation the results were as follows: The ACTH cells were irregularly shaped, with extended thin and long plasmatic processes which interdigitated with GH cells. The processes filled with secretory granules. Some of the Secretory granules aligning along the plasmatic membrane showed pale density. The flat cisternae of rough endoplasmic reticulum (RER) appeared to be slightly dilated. The sizes of the bodies of GH and PRL cells increased. In the GH cells there were numera media cisternae in RER, their Golgi complex was well developed, and the secretory granules were distributed to the periphery of the cell bodies. All these phenomenous showed the secretory activity of these cells was enhanced. The PRL cells contained well developed Golgi complex and abundant RER. In the experiment group of the visceral painful stimulation the results were as follows: There were more striking changes of parenchymal cells of anterior lobes in rats pituitary than those of the experimental group of the somatic painful stimulation. The cell bodies of ACTH, GH and PRL cells showed hypertrophy, the nucleus enlarged and nucleolus were relatively prominent. The dense granules decreased in number and the pale or empty visicles almost situated near the plasmic membrane in ACTH cells. In the GH cells large vacuoles were distributed throughout the cytoplasma. The number and density of the secretory granules decreased. In PRL cells the Golgi complex were extended, the dictyosomes increased, in addition, RER, polyribosomes and mitochandria were more aboundant than that in these normal cells. These cytological changes suggested secretory and synthetic activity of these cells were enhanced. At last, pain in relation to several hormones such as ?-endorphin, ?-LPH, ACTH and ?-MSH etc. were discussed by the author.