[Endocrine cells of the duodenal glands in various representatives of Primates]

The duodenum of four species of monkeys, belonging to the genera Macaca and Papio, has been investigated. In order to reveal argyrophil and argentaffin Ec-cells, Grimelius and Masson-Hamperl methods have been used, respectively. In all the species studied in the terminal parts and in the ducts of the duodenal glands presence of endocrine cells is noted; their amount, however, is considerably less than in crypts. Open and close types of endocrine cells++ have been revealed in the glands. A part of the endocrine cells population is argentaffin Ec-cells (about 40% in Papio and 80% in Macaca). This demonstrates participation of serotonin they produce in regulation of the duodenal glands functional activity. Dependence between taxonomic position of the species and degree of endocrine cells++ development in the duodenal glands has been followed. In particular, in representatives of Macaca amount of argyrophil and argentaffin in the glands is greater than in Papio. Possible reasons of the differences are discussed. Comparing the results on investigation of the glands in the primates with those previously obtained for representatives of Carnivora, a suggestion is made concerning some general principles in organization of the proper endocrinic apparatus of the mammalian duodenal glands.