Calcium accumulation in experimental hypertension.

At present, the significance of calcium accumulation in the aetiology of coronary artery disease (CAD) in humans is not known, except only to exacerbate the condition. In an attempt to understand ionic disturbances in vasculature derived from cardiovascular abnormalities, soft tissues from hypertensive models were examined. The study hypothesis was to see if basic cardiovascular regulatory sites in hypertensive models accumulated greater amounts of Ca2+. Calcium levels were measured by flame atomic absorption spectrophotometry in tissue derived from two types of hypertensive rabbits. Both models of hypertension developed mean arterial pressures of at least 50 mm Hg greater than those of controls over a 5-wk period. Significant increases in calcium levels were found in left ventricle and aorta derived from both hypertensive groups compared with controls. Renal cortex and medulla were not significantly different among any of the groups. These levels corroborate the findings of others which show increased calcium levels in cardiovascular tissues in experimental hypertension in rabbits. Although there have been several studies that have shown the relationship between calcium, hypertension and CAD, this is the first study to look at calcium accumulation rather that the effects of calcium channel blockers. The link between hypertension and calcium accumulation in a number of tissues may be important in the development of CAD and other cardiac dysfunction.