The Natriuretic Peptide (Onp-39) From Platypus (Ornithorhynchus anatinus) Venom Promotes Mast Cell Histamine Release.

Abstract

In this study we investigated the possibility that the C-type natriuretic peptide from platypus venom (ONP-39) contributes to the acute effects of envenomation, which include oedema, pain and erythema. These effects may result from the release of auto pharmacological mediators from mast cells. Using an in vitro assay we have demonstrated that both ONP-39 and the endogenous C-type natriuretic peptide (CNP-22) release histamine from rat peritoneal mast cells, an effect similar to the structurally homologous atrial natriuretic peptide (ANP) (Opgenorth et al., 1990, Peptides 11(5):1003-7). Two synthetic peptides, ONP-39(1-17) and ONP-39(18-39), corresponding to the N- and C- termini respectively, are equipotent, suggesting that ONP-39 and other natriuretic peptides do not act through conventional ANP receptors on mast cells. The ability of ONP-39 to promote histamine release suggests that it may contribute to the acute symptoms of envenomation.