Coronary vasodilator compared to cardiac effects of PY 108-068, a new dihydropyridine vasodilator, on isolated, blood-perfused dog-heart preparations.
|
| Abstract |
We evaluated coronary vasodilator and cardiac effects of PY 108-068 on isolated, blood-perfused sinoatrial (SA) node, atrioventricular (AV) node, and papillary muscle preparations of dogs. PY 108-068 was administered intra-arterially (i.a.). PY 108-068 increased (coronary) blood flow in all preparations. In SA node preparations, the drug produced a decrease in sinus rate and, in large doses, atrial standstill. In AV node preparations, the drug produced an increase in AV conduction time. Large doses caused second- or third-degree AV block, but only when injected into the artery supplying the AV node. The doses producing a 15% (nearly half maximum) decrease in sinus rate or a 15% (nearly half maximum) increase in AV conduction time were two to three times the doses that doubled coronary blood flow. In paced papillary muscle preparations, the drug produced a decrease in the force of contraction. However, the dose required to reduce the force of contraction of the papillary muscle by 50% was about 30 times the dose that doubled coronary blood flow. The drug was entirely ineffective on rate of ventricular automaticity. We conclude that PY 108-068 is not likely to produce reflex tachycardia when administered systemically in coronary vasodilator doses.
|
|---|---|
| Authors | Y Wada, K Satoh, N Taira |
| Journal | Journal of cardiovascular pharmacology (J Cardiovasc Pharmacol) 1984 Sep-Oct Vol. 6 Issue 5 Pg. 881-7 ISSN: 0160-2446 [Print] United States |
| PMID | 6209495 (Publication Type: Comparative Study, Journal Article) |
| Chemical References |
|
| Topics |
|
Join CureHunter, for free Research Interface BASIC access!
Realize the full power of the drug-disease research graph!