Free calcium concentration in platelets closely relates to blood pressure in normal and essentially hypertensive subjects.

Abstract

Calcium has been implicated in smooth muscle contraction, arterial resistance, and the pathophysiology of essential hypertension. Using the intracellularly trapped fluorescent dye quin2 , the free calcium concentration in platelets was found to be elevated in patients with borderline (n = 8, p less than 0.01) and established essential hypertension (n = 23, p less than 0.001) when compared with normotensive subjects (n = 30). There was a close correlation between intracellular free calcium and systolic blood pressure (n = 61, r = 0.882, p less than 0.001) as well as diastolic blood pressure (n = 61, r = 0.950, p less than 0.001). The slopes of the regression lines did not differ between the groups.

Free Calcium Concentration in Platelets of Patients with Essential Hypertension

“…The difference is statisti cally significant despite the remarkable overlap between the two goups. The observed values for [Ca2+], are slightly lower as compared with those reported by Erne et al [ 12], and we were not able to demonstrate a significant corre lation between [Ca2+]j and blood pressure values.…”

“…[Ca2+]i has been studied by the Quin 2 tech nique in platelets of patients with essential hypertension by Erne et al [12] and by Bruschi et al [13]. These Authors found a significant increase of [Ca2+], in platelets of hypertensive patients.…”

Abnormalities of platelet function in hypertension and diabetes.

“…13 Since the extent of this change was modulated by extracellular calcium, 13 it perhaps represents abnormal transport or storage of intracellular calcium in hypertensive platelets. 16 In addition, we demonstrated that agents such as prostaglandin E, are able to elevate cAMP levels in an exaggerated manner in SHR. 13 We have also shown that adenylate cyclase in platelets is stimulated by a calcium-dependent cytosolic protease.…”

Ethanol and platelet intracellular free calcium concentrations.

“…Platelet intracellular free calcium concentration has been shown to correlate positively with blood pressure in normal and hypertensive subjects (Erne et al, 1984;Sang & Devynck, 1986). While developing the assay we noticed that certain individuals had high platelet calcium levels on some days only, and a common factor appeared to have been alcohol consumption within the preceding 2-3 h. Since alcohol is a known risk factor for high blood pressure (Criqui et al, 1981;Cairns et al, 1984) this observation was potentially of great interest.…”