Blood pressure effects of acute hypercalcemia in normal subjects and thyroparathyroidectomized patients

The effect of acute hypercalcemia on blood pressure and plasma catecholamine levels was investigated in 10 normal subjects and in 5 patients completely thyroparathyroidectomized (TPTX) for a parathyroid cancer. In normal subjects, calcium infusion (15 mg/kg over 3 h) significantly increased plasma calcium and epinephrine levels and blood pressure. Plasma norepinephrine was increased only after 3 h of calcium infusion. In TPTX patients, calcium infusion increased significantly plasma calcium and epinephrine but not blood pressure. The percent increase in mean blood pressure during calcium infusion correlated with the concomitant percent increase in serum calcium in normal subjects (r = 0.71, p less than 0.001) but not in TPTX patients (r = -0.08). These data are in agreement with the hypothesis that the effect of calcium on arterial pressure is realized under intact parathyroid function.