[Enterochromaffin and enterochromaffin-like cells of the stomach during aging in rats].

In the gastric mucosal membrane of rats--mature, first old and late old age (9.5-20, 26.5-29 and 32.5-37 months) ultrastructure of serotonin-producing EC-cells and histamine-producing ECL-cells has been studied. By means of stereomorphometric methods volumes of nuclei, nucleoli, cytoplasm and its organelles, nuclear cytoplasmic index, amount of endocrine granules have been determined. Increasing volumes of EC- and ECL-cells and their organelles in the old age demonstrate certain development of adaptive changes, directed to maintenance of monoamines secretion at a necessary level. This is reached at the expense of increasing energetic and plastic expenditure. In the late old age intensification of adaptation, further growth of organelles volumes, responsible for energetic and plastic metabolism are kept for EC-cells. Increasing content of active granules in cytoplasm demonstrates an enhanced production of serotonin by every separate cells. In the same age in ECL-cells the adaptive processes decrease. Volumes of the cells and their all organelles sharply drops, the number of the active granules decreases; this should result in decreasing histamine production in the gastric mucous membrane.