Gender differences in some host defense mechanisms

Sexual dimorphism exists in the immune response. Both humoral and cell-medi ated immunity are more active in females than in males, and steroid gonadal hormones may play an important role in regulating this response. We have documented gender differences in several aspects of neutrophil and macrophage functions elicited by lipopolysaccharide (LPS) (endotoxin) treat ment and/or acute ethanol intoxication. In LPS-treated female rats, circula ting, neutrophils and alveolar macrophages are resistant to the deleterious effects of surgery and anesthesia on phagocytosis observed in male rats. T he generation of cytokine-induced neutrophil chemoattractant (CINC) by hepa tocytes and Kupffer cells of LPS-treated rats, as well as TNF-alpha secreti on by Kupffer cells and alveolar macrophages of acutely ethanol intoxicated rats are also gender dependent. The effects of alcohol on the immune response are expressed differently in males and females. In LPS plus ethanol-treated rats gender differences were noted in terms of adhesion molecule (CD11b/c) expression on circulating ne utrophils, and cytoskeletal reorganization in blood-recruited neutrophils a nd Kupffer cells. Nitric oxide (NO) plays an important role in inflammatory processes. We fou nd gender differences in NO production by alveolar macrophages of LPS-treat ed rats; this difference was abrogated by ethanol treatment. LPS tolerance and ethanol treatment modulate hepatic NO production in rats in a cell- and gender-dependent fashion, which may exert a protective influence against o xidative injury in the female liver.