Gender differences in the histamine and serotonin content of blood, peritoneal and thymic cells: a comparison with mast cells.

The serotonin and histamine content of mast cells and white blood cells in adult male and female rats was compared, using a flow cytometric immunological method. Serotonin was significantly higher in female peritoneal mast cells, peritoneal monocyte-ganulocyte-macrophage cells, blood lymphocytes and blood thymocytes. Histamine was significantly higher in female peritoneal monocyte-granulocyte-macrophage cells, and blood lymphocytes, monocytes and granulocytes, but was significantly less in thymocytes. Peritoneal lymphocytes and the monocyte-granulocyte-macrophage group contained significantly more histamine than mast cells. These experiments call attention to gender differences in the levels of biogenic amines in cells participating in defence reactions, and to the possible non-unique role of mast cells in serotonin and histamine supply.