MECHANISMS UNDERLYING THE CARDIOVASCULAR ACTION OF A NEW DIHYDROPYRIDINE VASODILATOR, YC‐93

K. Satoh, T. Yanagisawa, N. Taira

Research output: Contribution to journalArticlepeer-review

58 Citations (Scopus)

Abstract

1.The mechanisms underlying the cardiovascular action of YC‐93, a new dihydropyridine vasodilator with cyclic AMP phosphodiesterase inhibitory activity, was investigated by comparing its effects wth those of papaverine in various isolated, blood‐perfused heart preparations of the dog. 2. In all preparations YC‐93 injected into the nutrient arteries produced a dose‐dependent increase in blood flow, and in this respect YC‐93 was about twenty times more potent than papaverine on a weight basis. 3. In sinoatrial node preparations YC‐93 injected into the sinus node artery decreased sinus rate in a dose‐dependent manner, and in large doses produced atrial standstill. 4. In atrioventricular (a.v.) node preparations YC‐93 injected into the a.v. node artery increased a.v. conduction time in a dose‐dependent manner, and in large doses produced a second or third degree block of a.v. conduction. However YC‐93 injected into the anterior septal artery scarcely affected a.v. conduction. 5. In spontaneously contracting papillary muscle preparations YC‐93 injected into the anterior septal artery failed to affect ventricular automaticity in doses which markedly decreased developed tension of papillary muscles. 6. In papillary muscle preparations driven at a fixed rate YC‐93 injected into the anterior septal artery produced a dose‐dependent decrease in developed tension of papillary muscles. 7. Unlike YC‐93, papaverine decreased a.v. conduction time in a.v. node preparations and increased developed tension of papillary muscle preparations. 8. The cardiac effects of YC‐93 elucidated in the present experiments are characteristic of calcium‐antagonistic vasodilators. The action of YC‐93 as an inhibitor of cyclic AMP phosphodiesterase does not appear to play a role in its cardiac action.

Original languageEnglish
Pages (from-to)249-262
Number of pages14
JournalClinical and Experimental Pharmacology and Physiology
Volume7
Issue number3
DOIs
Publication statusPublished - 1980 Jun

Keywords

  • atrioventricular conduction
  • calcium antagonists
  • contraction
  • coronary blood flow
  • coronary vasodilator
  • dihydropyridine
  • dog
  • papaverine
  • phosphodiesterase inhibitors

ASJC Scopus subject areas

  • Physiology
  • Pharmacology
  • Physiology (medical)

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