The effects on renal hemodynamics and salt-water handling of equipotent doses of the cardioselective beta-blocker metoprolol (M, 100 mg) and of the non-selective (intrinsic sympathetic activity) beta-antagonist pindolol (P, 10 mg) were compared in 30 WHO Grade 1-2 hypertensive men. M lowered pulse rate more than P. Systolic pressure was equally reduced by both agents, and diastolic and mean pressures were decreased only after P. Glomerular filtration rate was not significantly altered by either antagonist, and renal blood flow decreased by approximately 11% both after M and P. Renal vascular resistance was unchanged after P, and was increased by 10% after M. It is concluded that, like the effects on central haemodynamics, ISA is more important in the renal response to beta-adrenoceptor blockade than is beta-receptor selectivity.

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