Divergent natriuretic action of calcium channel antagonists in mongrel dogs: renal haemodynamics as a determinant of natriuresis

This study examined the effects of different types of calcium channel antagonists on renal haemodynamics and natriuresis. The intravenous infusion of nifedipine (L-type blocker), efonidipine (L/T-type blocker) or mibefradil (predominant T-type blocker) into anaesthetized dogs elicited similar, albeit modest, reductions in blood pressure. Nifedipine (1 microgram.min(-1).kg(-1)) increased renal plasma flow (RPF) (23+/-6%; P