Effect of the calcium antagonist nicardipine on the pressor action of endothelin.
To evaluate hemodynamic actions of endothelin, anesthetized normal dogs and dogs with two doses of nicardipine received endothelin (400 pmol/kg, i.v.). Normal dogs showed an increase in blood pressure (BP) associated with an early (5 min) increase in cardiac output (CO) and a later (60 min) increase in total peripheral resistance (TPR). The lower dose of nicardipine (0.01 mg/kg/h) abolished the latter vasoconstrictive BP elevation. Dogs with the higher dose of nicardipine (0.1 mg/kg/h) did not show any changes in BP, CO or TPR. Thus, endothelin has both cardiostimulatory and vasoconstrictive actions, depending on the degree of calcium influx.
Department of Geriatric Medicine, Osaka University Medical School, Japan.
A
A
Otsuka
H
H
Mikami
K
K
Katahira
T
T
Tsunetoshi
K
K
Kohara
A
A
Moriguchi
K
K
Minamitani
T
T
Ogihara
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects*; D002302:Cardiac Output / Q000187:drug effects; D003714:Denervation; D004285:Dogs; D016232:Endothelins; D005260:Female; D006339:Heart Rate / Q000187:drug effects; D008297:Male; D009529:Nicardipine / Q000494:pharmacology*; D010455:Peptides / Q000494:pharmacology*; D012018:Reflex / Q000187:drug effects; D014655:Vascular Resistance / Q000187:drug effects
D016232:Endothelins; D010455:Peptides; D009529:Nicardipine