Effect of nicardipine on the relationship of renal blood flow and of renal vascular resistance to perfusion pressure in dog kidney.
The effect of nicardipine, a Ca channel blocker, on autoregulation of renal blood flow and perfusion pressure-vascular resistance relationship has been investigated in perfused kidneys of anaesthetized dogs. In control animals excellent autoregulation of renal blood flow and pressure-dependent elevation of vascular resistance were observed above 100 mmHg of perfusion pressure. However, intra-arterial infusion of nicardipine at doses of 3 and 10 micrograms min-1 showed dose-dependent impairment of the autoregulatory response and of elevation of vascular resistance. Infusion of nicardipine (2.5 micrograms min-1) into the renal artery also inhibited renal vasoconstriction induced by YC-170, a Ca channel activator. These results suggest that the inhibitory effect of nicardipine upon renal autoregulation may be due to its Ca2+ channel blocking action.
Ogawa
N
N
Department of Pharmacology and Toxicology, Hatano Research Institute, Food and Drug Safety Center, Kanagawa, Japan.
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002120:Calcium Channel Agonists / Q000494:pharmacology; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005260:Female; D008297:Male; D009529:Nicardipine / Q000494:pharmacology*; D009543:Nifedipine / Q000031:analogs & derivatives / Q000494:pharmacology; D010477:Perfusion; D012079:Renal Circulation / Q000187:drug effects*; D014655:Vascular Resistance / Q000187:drug effects*; D014661:Vasoconstriction / Q000187:drug effects
D002120:Calcium Channel Agonists; C046721:YC 170; D009529:Nicardipine; D009543:Nifedipine