RESUMEN
The effect of sex steroids on the plasma levels of alfa2-macroglobulin (alfa-2M) was investigated to explain the sexual dimorphism observed in response to the injuries caused by ip administration of 5 microng endotoxin. Mean serum alfa2-M concentrations were lower in female (46.82 ñ8.10 arbitrary units) than in male injured rats (82.94 ñ 9.22 arbitrary units). a reduction of plasma alfa2-M levels was observed after orchidectomy, and the administration of 1 mg testosterone to the same animals increased the response. The same response pattern wa observed in ovariectomized rats under the same treatment. The response of androgenized rats (78.93 ñ 12.81 arbitrary units) to injury was similar to the male response. These results suggest the importance of testosterone as the major determinant of this sex-dependent response