[Effects of m-nifedipine and nifedipine given intraduodenally on coronary flow, myocardial oxygen, and carbon dioxide metabolism in dogs].
In anesthetized dogs intraduodenal administration of m-nifedipine (m-Nif) 0.4 mg.kg-1, coronary flow increased from 708 +/- 72 to 880 +/- 150 ml.min-1.kg-1 (+24%) at 5 min, to 1976 +/- 350 ml.min-1.kg-1 (+179%) at 30 min, and to 998 +/- 250 ml.min-1.kg-1 (+41%) at 4 h. At the dose of nifedipine (Nif), coronary flow increased from 778 +/- 91 to 1080 +/- 90 ml.min-1.kg-1 (+39%) at 3 min and to 1836 +/- 280 ml.min-1.kg-1 (+136%) at 90 min. m-Nif was more 43% potent than Nif and the duration of action of m-Nif was longer. m-Nif reduced heart rate by -39%, while Nif reduced only -11%. m-Nif increased coronary sinus O2 content and reduced MVO2, and no difference was seen between these 2 drugs. However, the rate of CO2 production with m-Nif was reduced to a greater degree than that of Nif. The results indicated that m-Nif was more beneficial in alleviating myocardial ischemia than that of Nif.
Rao
M R
MR
Department of Cardiovascular Pharmacology, Nanjing Medical College, China.
Liu
Q Y
QY
Jia
S L
SL
D000818:Animals; D001794:Blood Pressure / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects*; D004285:Dogs; D004386:Duodenum; D006339:Heart Rate / Q000187:drug effects; D007536:Isomerism; D009206:Myocardium / Q000378:metabolism; D009543:Nifedipine / Q000494:pharmacology*; D010101:Oxygen Consumption / Q000187:drug effects*
D009543:Nifedipine