Occurrence and frequency of enterochromaffin cells in the intestine of birds.

The occurrence and frequency of enterochromaffin cells in the intestine of 14 separate species of birds, the quantitative variations in the several sections of the intestine and the quantitative changes in the embryonic and postembryonic development of Anas platyhynchos have been investigated by the Protargol-reaction of Bodian and the fluorescence method of Falck and Hillarp. Enterochromaffin cells are concentrated in the crypts of Lieberkühn in first line. They have been found in all investigated species but in various frequency. The enterochromaffin cells exist frequently in herbivorous species, scarcely in carnivorous. The number of enterochromaffin cells increase from the duodenum to the colon. The enterochromaffin cells appear in the intestine of the duck embryo beginning with the 15th day of embryonic life. The number increase related with the age of the duckling. The content has been identified as 5-hydroxy-tryptamine by the colour of fluorescence and depletion of all enterochromaffin cells following reserpine administration.