title: Direct cardiac effects of vasopressin and their reversal by a vascular antagonist.
abstract: We studied the direct cardiac effects of arginine vasopressin (AVP) by use of an isolated working rat heart model perfused with Krebs-Henseleit medium. At a concentration of 878 +/- 15 pg/ml, AVP produced significant (P less than 0.05) decreases in coronary flow (-31 +/- 2%); myocardial O2 consumption (-12 +/- 2%); left ventricular peak systolic pressure (-5 +/- 1%); dP/dtmax (-7 +/- 1%); -dP/dtmax (-6 +/- 3%); peak aortic flow rate (-5 +/- 1%); stroke work (-3 +/- 1%); peak power (-8 +/- 1%); and total output (-3 +/- 1%). Aortic output increased significantly (+7 +/- 1%) as did arteriovenous O2 difference (+108 +/- 14 mmHg); left ventricular end-diastolic pressure (+0.4 +/- 0.1 mmHg); efficiency (+1.5 +/- 0.4%); and rate of lactate release (+1.27 +/- 0.21 nmol/ml perfusate/min). Dose-response relationships were studied at 9 +/- 1, 25 +/- 1, 75 +/- 3, 303 +/- 15, and 817 +/- 42 pg AVP/ml. Significant dose-dependent depression of coronary flow occurred at the three highest AVP concentrations; cardiac function was significantly depressed at the highest dose. The AVP analogue d(CH2)5[Tyr(Me)]AVP (20 ng/ml) completely reversed the cardiac effects attributed to AVP. The data indicate that AVP is a potent direct coronary constrictor that produces myocardial ischemia and decreased contractile function at AVP concentrations that are observed in some pathophysiologic states.(ABSTRACT TRUNCATED AT 250 WORDS)
mesh_terms: D000818:Animals; D001127:Arginine Vasopressin / Q000037:antagonists & inhibitors / Q000097:blood / Q000494:pharmacology*; D002302:Cardiac Output / Q000187:drug effects; D003326:Coronary Circulation / Q000187:drug effects; D006321:Heart / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009200:Myocardial Contraction / Q000187:drug effects; D010100:Oxygen / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains
chemical_list: D001127:Arginine Vasopressin; D010100:Oxygen