PROBLEM: Female sex hormones modulate a variety of humoral and cell-mediated immunologic functions. In this study, the effects of estrogen, progesterone, and testosterone on the chemiluminescence (CL) response and phagocytic ability of male rat peritoneal macrophages (Mφ) were examined.
METHOD: In Mφ pretreated with 10−2 ng/ml of 17β-estradiol (E2) for 20 hours, the CL generated in response to phorbol myristate acetate (PMA), 1,2-dioctanoyl-rac-glycerol (C8:0), or opsonized zymosan (OZ) was significantly increased by 135%, 140%, and 136% of control values, respectively. In addition, Mφ treated with 10−5 ng/ml or 10 ng/ml of E2 exhibited a significantly greater PMA-or OZ-stimulated CL response than did untreated controls.
RESULTS: At 10−2 ng/ml, progesterone enhanced and testosterone reduced the CL response, but these changes were not statistically significant. In time course studies, the PMA-stimulated CL response of Mφ treated with 10−2 ng/ml of E2 or progesterone for 5 h was significantly less than that of the untreated group. In the presence of endotoxin (12 pg/ml), the CL response in Mφ treated with E2 or testosterone was significantly depressed as compared to untreated controls. Phagocytosis of opsonized sheep erythrocytes also was significantly enhanced (140% to 190% of control) when Mφ were pretreated with 10−12 M to 10−8 M of either E2 or progesterone.
CONCLUSIONS: These findings suggest that, at physiological concentrations, E2 is capable of modulating both CL generation and phagocytic uptake by Mφ in a manner not shared by other steroid hormones.