Albumin Transcapillary Escape Rate and Plasma Volume during Long-Term Beta-Adrenergic Blockade in Essential Hypertension

Treatment of 10 patients with essential hypertension was found to reduce significantly the abnormally high transcapillary escape rate of albumin (fraction of intravascular albumin mass that passes to the extravascular space per unit time) from 7.1 to 5.7 per cent/hour (normal value 5.6 ± S.D. 1.1). The albumin outflux (amount of intravascular albumin that passes to the extra-vascular space per unit time) decreased from 8.7 to 6.8 g/hour. This was found by determining the disappearance of intravenously injected 131I-human serum albumin during the first 60 minutes after i.v. injection before and after 3 to 4 months of beta-adrenergic blocking treatment that practically normalized the blood pressure (mean 171/116 → 144/98 mm Hg). The decrease in transcapillary escape rate correlated significantly with the reduction in blood pressure. Plasma volume was not affected by treatment.