The functional morphology of the pulmonary neuroendocrine cells in the lung of larval and adult Rana ridibunda(amphibia-anura)

Abstract

The distribution and functional morphology of neuroendocrine cells (PNECs) were studied in the lung of tadpoleand adult Rana ridibunda. The responses of PNECs to different experimental conditions were investigated inadult frog lungs. In tadpole lungs, bombesin- and somatostatin immunoreactive (IR) PNECs were found in theinner-lining epithelium. In adult frogs kept in cold water (+ 4 $^ oC$), mostly serotonin- and bombesin-IR cells hadstored secretory material as well as serotonin-IR cells with released secretion, while somatostatin-IR cells withlimited secretory material were scarce. In the dry aquarium, somatostatin-IR cells of adult frogs were at varioussecretory stages. In conclusion, the activities of PNECs varied by depending on the amount of pulmonarycontribution of lungs into respiration.