AJP - Lung Cellular and Molecular Physiology, Vol 264, Issue 4 387-L390, Copyright © 1993 by American Physiological Society
Heparin inhibits histamine release from canine mast cells
N. Inase, R. E. Schreck and S. C. Lazarus
Cardiovascular Research Institute, University of California, San Francisco 94143.
To determine the role of heparin in mast cell exocytosis, we studied the
effect of heparin on histamine release induced by compound 48/80 or calcium
ionophore A23187 in canine mastocytoma cells (BR). Heparin caused
concentration-dependent inhibition of compound 48/80-induced histamine
release from mast cells (n = 4; P < 0.05) with a mean inhibitory
concentration of 0.14 +/- 0.01 U/ml (mean +/- SE). Mean maximal inhibition
was 69.3 +/- 2.0%. In contrast, heparin had no effect on calcium ionophore
A23187-induced histamine release. Although benzyl alcohol, a preservative
of pharmaceutical heparin, had no effect, purified heparin produced a
similar inhibitory effect on compound 48/80-induced histamine release (n =
4; P < 0.05). The inhibitory effect of heparin on histamine release was
rapid and was eliminated by washing cells. Dextran sulfate, a
polysaccharide with negative charge density, produced a similar inhibitory
effect on compound 48/80-induced histamine release (n = 4; P < 0.05). We
conclude that heparin inhibits compound 48/80-induced exocytosis in mast
cells probably by its negative charge density.
