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. 1988 Aug 15;254(1):147–153. doi: 10.1042/bj2540147

Alcohol-induced stimulation of phospholipase C in human platelets requires G-protein activation.

R Rubin 1, J B Hoek 1
PMCID: PMC1135050  PMID: 3140795

Abstract

In previous studies we have demonstrated that ethanol activates hormone-sensitive phospholipase C in intact human platelets, resulting in the mobilization of intracellular Ca2+ and platelet shape change. The present study aims to localize further this effect of ethanol by examining its interaction with the regulation of phospholipase C in a permeabilized cell system. In platelets permeabilized with a minimal concentration (18 micrograms/ml) of saponin, ethanol by itself did not activate phospholipase C. However, ethanol potentiated the activation of phospholipase C in response to the non-hydrolysable GTP analogue GTP[S] (guanosine 5'-[gamma-thio]triphosphate), an effect similar to that observed with thrombin. Ethanol also potentiated the response to fluoride, which acts directly on G-proteins. Other short-chain alcohols also stimulated phospholipase C in a synergistic manner with GTP[S]. The ability of specific alcohols to stimulate phospholipase C was directly related to their respective lipid-solubilities, as determined by their partition coefficients. Moreover, the potencies of each alcohol correlated with their ability to elicit Ca2+ mobilization and shape change in intact platelets. These effects of ethanol were eliminated by a disruption of receptor-phospholipase C coupling induced by the addition of higher concentrations of saponin. These data indicate that the activation of phospholipase C by ethanol may occur by affecting protein-protein interactions in the signal-transduction complex involving GTP-binding regulatory proteins.

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Selected References

These references are in PubMed. This may not be the complete list of references from this article.

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