Is there a possibility of intrasystem regulation by hormones produced by the immune cells? Experiments with extremely low concentrations of histamine.

The effect of histamine in 10 -9 , 10 -12 , 10 -15 and 10 -18 molar concentrations was studied on the beta-endorphin and triiodothyronine (T 3 ) content of peritoneal immune cells (lymphocytes, monocyte-granulocyte group and mast cells), using immunocytochemical flow cytometric method. The lower concentrations (10 -15 and 10 -18 M) were effective, where endorphin content was significantly lowered and T 3 content was significantly elevated. The results call attention to the extreme sensitivity of histamine receptors in this hormonal index and to the specific response by hormone production to histamine, in the immune cells. The new data support the earlier hypothesis, that there is a hormonal network inside the immune system.