Effects of diltiazem (CRD-401) on developed coronary collaterals in the dog.
The effect of diltiazem (CRD-401) on coronary collaterals was studied in the dog. The anterior descending branch of the left coronary artery was occluded for 4 to 6 weeks by an ameroid constrictor. In these dogs, the retrograde flow (RF) from the peripheral coronary artery and peripheral coronary pressure (PCP) were significantly higher than those in acute coronary-ligated dogs, suggesting the development of large supraepicardial intercoronary anastomoses. Diltiazem (100 mug/kg i.v.) increased circumflex blood flow (CBF) for several min, while nitroglycerin (10 mug/kg i.v.) increased CBF transiently after which CBF decreased to below control values. Diltiazem (100 mug/kg) and nitroglycerin (10 mug/kg) increased RF/MAP (mean aortic pressure) and PCP/MAP and these increases lasted longer than that of CBF. Diltiazem also increased RF in doses of 100 mug/kg or 20 mug/kg/min. Therefore, diltiazem possesses the property of dilating coronary collaterals thus causing redistribution of intramyocardial blood flow. In acute preparations, however, both diltiazem and nitroglycerin showed no significant changes in PCP/MAP and RF/MAP.
D000818:Animals; D001552:Benzazepines / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D003097:Collateral Circulation / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D003331:Coronary Vessels / Q000187:drug effects* / Q000502:physiology; D004110:Diltiazem / Q000494:pharmacology*; D004285:Dogs; D008026:Ligation; D008297:Male; D005996:Nitroglycerin / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
D001552:Benzazepines; D014665:Vasodilator Agents; D004110:Diltiazem; D005996:Nitroglycerin