Corticotropin-releasing hormone enhances the superoxide anion production of rabbit peritoneal macrophages stimulated with N-formyl-methionyl-leucyl-phenylalanine.

Effects of corticotropin-releasing hormone (CRH) on the superoxide anion (O2-) production in macrophages (M phi s) were investigated. CRH by itself failed to induce the O2- production of rabbit peritoneal M phi s elicited with thioglycollate medium. However, M phi s preincubated with CRH showed significant enhancement of O2- production following stimulation with a chemotactic peptide, N-formyl-methionyl-leucyl-phenylalanine (FMLP), at CRH concentrations from 10(-10) to 10(-7) M. Maximal enhancement of O2- production was obtained with 10 min preincubation with CRH for FMLP stimulation. CRH had no effect on O2- production when stimulated with phorbol 12-myristate 13-acetate. Neither corticotropin nor beta-endorphin augmented the O2- production induced with FMLP. These results indicate that CRH has priming effects on FMLP-induced O2- production of rabbit peritoneal M phi s, although the underlying mechanism remains to be clarified.