Renal hemodynamics in canine DOCA-salt hypertension: effect of calcium channel blockade.
Systemic arterial blood pressure (BP), renal blood flow (RBF), and renal vascular resistance (RVR) were followed for 3-4 wks during the progression of DOCA-salt hypertension in the conscious dog. Accompanying the gradual increase in BP was an increase in RBF; however, RVR was unchanged. The hypertension was totally reversed 5-7 days after cessation of DOCA-salt treatment, but the increase in RBF persisted, presumably as a result of renal hypertrophy. Renal adrenoceptor blockade with prazosin (6 dogs) and prazosin plus idazoxan (4 dogs) caused a comparable decrease in BP in the normotensive and DOCA-salt hypertensive dog; however, RVR was decreased only in the normotensive. Similar results were obtained during ganglionic blockade with hexamethonium. The i.v. infusion of diltiazem for 1 wk restored BP of the hypertensive dog to a normotensive level, and hexamethonium given i.v. had little further effect on either BP or RVR. These results suggest a non-neurogenically mediated mechanism of canine DOCA-salt hypertension that is susceptible to calcium channel blockade.
Zimmerman
B G
BG
Department of Pharmacology, University of Minnesota, Minneapolis 55455.
Raich
P C
PC
D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D002121:Calcium Channel Blockers / Q000494:pharmacology*; D003900:Desoxycorticosterone; D004146:Dioxanes / Q000494:pharmacology; D004285:Dogs; D006339:Heart Rate / Q000187:drug effects; D006584:Hexamethonium Compounds / Q000494:pharmacology; D006973:Hypertension / Q000139:chemically induced / Q000503:physiopathology*; D019329:Idazoxan; D009392:Nephrectomy; D011224:Prazosin / Q000494:pharmacology; D012079:Renal Circulation / Q000187:drug effects*
D000317:Adrenergic alpha-Antagonists; D002121:Calcium Channel Blockers; D004146:Dioxanes; D006584:Hexamethonium Compounds; D003900:Desoxycorticosterone; D011224:Prazosin; D019329:Idazoxan