DIFFERENCE IN PLATELET CYTOSOLIC CALCIUM RESPONSE TO THROMBIN IN ALCOHOLIC WITHDRAWAL AND SOBER PATIENTS

Objective: The protective role of moderate alcohol intake in coronary heart disease is well known. However, chronic alcoholics are reported to have higher incidence of cardiovascular, endocrine and hematological diseases. It is possible that the etiology of increased cardiovascular diseases in chronic alcohol dependent patients is related to platelet reactivity. The objective of this study is to investigate the cytosolic calcium and its response to thrombin in the platelets from chronic alcoholic patients who are in the state of withdrawal and alcoholic patients who are sober. Method: Platelets were harvested from 14 normal controls and 25 alcohol dependent patients (18 in withdrawal state and 7 in sober state). Using the fluorescent calcium probe fura-2, cytosolic calcium ([Ca2+](i)) in platelets during the resting state and when stimulated by 0.1 U/ml of thrombin were measured. Response to thrombin was expressed as %[Ca2+](i) increase over resting [Ca2+](i). Results: Percentage release of cytosolic calcium in response to thrombin (%[Ca2+](i)) was significantly higher (ANOVA, p < .0001) in the alcoholic withdrawal (328.9%) than the alcoholic sober (121.3%) and normal controls (95.1%). Conclusions: The data showed an increase in cytosolic calcium response to thrombin in platelets from alcoholics during withdrawal phase. This enhancement in platelet reactivity may be associated with cardiovascular morbidity in the withdrawal state of alcohol dependency.