MIDKINE INDUCES HISTAMINE-RELEASE FROM MAST-CELLS AND THE IMMEDIATE CUTANEOUS RESPONSE

Midkine is a product of a retinoic acid-responsive gene and exerts a v ariety of biological activities. The aim of our investigation is to de termine whether human midkine have histamine-releasing effects on mast cells, and to show the evidence of the inflammation induced by midkin e. Midkine induced histamine release from rat peritoneal mast cells wi th a rapid response in a dose-dependent manner. Extracellular calcium inhibited the histamine release induced by midkine in a dose-dependent manner. Pertussis toxin and benzalkonium chloride inhibited the hista mine release induced by midkine. Gi-proteins exert an effect on the hi stamine release of midkine. The immediate cutaneous response induced b y midkine was positive. These results suggest that midkine may take pa rt in some inflammation via histamine release from mast cells.