Role of positive charges of neuropeptide Y fragments in mast cell activation.

The incubation of neuropeptide Y (NPY) or of NPY C-terminal fragments with rat peritoneal mast cells resulted in a dose-dependent histamine secretion (10(-9)-10(-5) M). A linear correlation between the number of net positive charges of the peptides and histamine release potencies was obtained. The histamine secretion induced by NPY fragments was inhibited by the treatment of mast cells with benzalkonium chloride and pertussis toxin indicating the involvement of G proteins.