[Seasonal changes in the endocrine cells of the gastric epithelium of Rana temporaria].

By means of the light and electron microscopy methods histotopography, quantity and ultramicroscopic organization of endocrine cells (EC) have been studied in gastric epithelium of the frog (Rana temporaria) during various periods of its life: hibernation, awakening, active life. At all the periods of life 8 types of EC are revealed. Depending on the season, certain changes both in their amount and ultrastructural organization are observed. Decreasing amount of EC is noted during hibernation and their increase in spring during awakening and in summer. Quantity of enterochromaffin cells is not subjected to seasonal fluctuations. This is explained by the fact that in hibernation these cells are also at their active functional state, since they produce serotonin necessary for maintaining deep hypothermia, specific for hibernating animals.