Gamma-thrombin-induced phospholipase A2 activation in rabbit platelets: comparison with alpha-thrombin |
| |
Authors: | L Touqui M Jandrot-Perrus B B Vargaftig |
| |
Affiliation: | Unité de Pharmacologie Cellulaire, Unité Associée Institut Pasteur/INSERM N. 285, Paris, France. |
| |
Abstract: | gamma-Thrombin stimulated release of [3H]arachidonic acid ([3H]AA) accompanied by a significant production of PAF and lyso-PAF by rabbit platelets. These responses, which reflect PLA2 activation, were observed after a prolonged lag and to a lower extent when compared to those induced by alpha-thrombin which evoked a much higher elevation in intracellular calcium. This elevation together with [3H]AA release were markedly reduced by EDTA. However, addition of ionophore A23187 enhanced the release of [3H]AA by gamma-thrombin to the levels similar to those of alpha-thrombin. We conclude that gamma-thrombin is able to activate PLA2 and suggest that calcium influx may be a limiting factor for this activation. |
| |
Keywords: | |
|
|