ELEVATED CYTOSOLIC-FREE CALCIUM CONCENTRATIONS IN PLATELETS OF HYPERTENSIVE DRINKERS - A WEAK ASSOCIATION WITH ALCOHOL-CONSUMPTION

Although the mechanisms of alcohol related hypertension remain unknown , it has been hypothesised that alcohol causes the accumulation of cal cium ions (Ca2+) in vascular smooth muscle cells, resulting in the ele vation of vascular tonus. To evaluate this contention, intra platelet free calcium concentrations (platelet [Ca2+]i) were determined in 20 y oung adult men, i.e. five each of hypertensive heavy drinkers, hyperte nsive light drinkers, normotensive heavy drinkers, and normotensive li ght drinkers. Platelet [Ca2+]i were higher in the ten hypertensives th an in the ten normotensives, irrespective of alcohol consumption. The hypertensive drinkers also showed higher levels of serum gamma-glutamy l transpeptidase (gamma-GTP) and parathyroid hormone (PTH). Platelet [ Ca2+]i in the total 20 subjects did not correlate with alcohol consump tion, but correlated positively with serum gamma-GTP levels and SBP. T hese preliminary study results do not support the contention that Ca2 accumulates in the vascular smooth muscle cells of humans as a result of chronic alcohol consumption. The significance of elevated platelet [Ca2+]i observed in the hypertensive heavy drinkers in the pathogenes is of alcohol related hypertension remains obscure.