Time course of regression of vascular structural changes and its relation to cytosolic free calcium in hypertensives after nilvadipine treatment.

The objective of this study was to assess the regression of vascular structural changes seen in essential hypertension after long-term monotherapy with a calcium antagonist and to clarify the relations to cytosolic free calcium and neurohumoral factors. Blood pressure, minimal vascular resistance (MVR) by strain-gauge plethysmography, cytosolic free calcium in platelets ([Ca2+]i) by Quin 2 method, plasma renin activity (PRA) and plasma aldosterone concentration (PAC), plasma noradrenaline (PNA) and parathyroid hormone (PTH) were measured in 14 essential hypertensives during a placebo period and 2 and 6 months after anti-hypertensive treatment with nilvadipine. Blood pressure decreased from 174 +/- 10/104 +/- 8 mm Hg during the placebo period to 154 +/- 13/93 +/- 14 mm Hg 2 weeks after nilvadipine, and the hypotensive effects were found throughout the 6-month period. Although increased MVR seen in hypertensives did not change after 2 months (from 2.1 +/- 0.7 to 1.9 +/- 0.6 mm Hg/ml/min per 100 ml tissue (PRU), NS), MVR decreased significantly at 6 months (1.6 +/- 0.4, PRU, P < 0.05). Elevated [Ca2+]i seen in hypertensives during the placebo period decreased significantly 2 months after nilvadipine treatment (156 +/- 26 and 140 +/- 27 nM, P < 0.01). The changes in MVR were associated with those in [Ca2+]i 6 months after nilvadipine (r = 0.56, P < 0.05). However, the changes in MVR did not correlate with those in PRA, PAC, PNA or PTH.(ABSTRACT TRUNCATED AT 250 WORDS)