EFFECT OF NITROVASODILATORS ON THE RHYTHMIC CONTRACTIONS OF GUINEA-PIG ISOLATED SPHINCTER OF ODDI


GOCER F., YARIS E., TUNCER M., KAYAALP S.

ARZNEIMITTELFORSCHUNG-DRUG RESEARCH, vol.45, no.7, pp.809-812, 1995 (SCI-Expanded) identifier identifier identifier

  • Publication Type: Article / Article
  • Volume: 45 Issue: 7
  • Publication Date: 1995
  • Journal Name: ARZNEIMITTELFORSCHUNG-DRUG RESEARCH
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, International Pharmaceutical Abstracts
  • Page Numbers: pp.809-812
  • Keywords: AMYL NITRITE, CAS 87-33-2, CAS 8017-89-5, CAS 14402-89-2, ISOSORBIDE DINITRATE, NITROVASODILATORS, SODIUM NITROPRUSSIDE, OPOSSUM SPHINCTER, METHYLENE-BLUE, MORPHINE, DRUGS, STIMULATION, RELAXATION, MECHANISM, PETHIDINE, HORMONES, PRESSURE
  • Karadeniz Technical University Affiliated: No

Abstract

The effects of amyl nitrite (CAS 8017-89-8) isosorbide dinitrate (CAS 87-33-2) and sodium nitroprusside (CAS 14402-89-2), on the acetylcholine-induced tachyrhythmia (greater than 9 waves/min) were investigated in the isolated guinea-pig sphincter of Oddi. Acetylcholine (10(-3) mol/l) produced an initial rapid rise in tension, the peak being followed by a gradual decrease associated with the initiation of the peristaltic waves. Nitrovasodilators significantly decreased the initial response to acetylcholine. Methylene blue (5 x 10(-5) mol/l), a soluble guanylate cyclase inhibitor increased the tonic response to acetylcholine and reversed the inhibition caused by nitrovasodilators. The frequency and amplitude of peristaltic waves were decreased by nitrovasodilators. Methylene blue significantly increased both the frequency and amplitude of peristaltic waves, however; it did not reverse the inhibition caused by nitrovasodilators tested. Results suggest that nitrates decrease the acetylcholine-induced contraction and peristaltism of isolated guinea-pig sphincter of Oddi and NO released by acetylcholine may partially suppress its own tonic contractile response.