Effect of adrenocorticotropic hormone (ACTH) and insulin on the phagocytic capacity of Tetrahymena.

Adrenocorticotropic hormone (ACTH) and insulin negatively influenced the phagocytic activity of Tetrahymena. The two hormones had diverse effects after 4 hr of treatments on no-test-particle containing, "0-cells". At this time the number of "0 cells" was significantly lower in the ACTH-treated groups, while in the insulin-treated groups there was an increase of "0-cells" compared to the control and to the results of the starting experiment. Considering previous results, when small molecular weight hormones, if did at all, positively influenced phagocytosis in Tetrahymena, the experiments call the attention to the differences caused by the size of the signal molecules. In the light of the literary data on hormone effects to phagocytosis in mammals and men, the similarity of the effects in species being very far from each other in evolution, could be concluded.