CALCA and peritonitis: CGRP is a potent anti-inflammatory mediator; it is thought to inhibit type 1 cytokines (eg, interleukin [IL]-12 and interferon γ) and to enhance the production of IL-10, one of the most immunosuppressive cytokines.109,110 Gomes et al12 observed anti-inflammatory effects of CGRP in models of acute peritonitis, reducing the recruitment of neutrophils induced by treatment with lipopolysaccharides.