Hisayoshi Fujita (1), Minoru Yoshiyama (1,*), Kazuhide Takeuchi (1),
Takashi Omura (1), Hiroyuki Yamagishi (1), Hiroshi Iwao (2), Katuyuki Miura
(2) and Junichi Yoshikawa (1)
(1) First Department of Internal Medicine and (2) Department of Pharmacology, Osaka City University Medical School, Osaka 545-8586, Japan
(*) To whom correspondence should be addressed.
Abstract: This study was designed to assess the effect of a nonpeptide vasopressin V1-receptor antagonist, OPC-21268, and a vasopressin V2-receptor antagonist, OPC-31260, on hemodynamics in the early phase and the late phase after myocardial infarction in rats. In the early phase, OPC-21268 (30 mg/kg/day) or OPC-31260 (30 mg/kg/day) was orally administered from day 1 to day 5 after the operation; and hemodynamics were measured at day 5, in the late phase from 10 weeks to 11 weeks and measured at the end of 11 weeks. In the early phase, OPC-21268 reduced the left ventricular end-diastolic pressure (LVEDP) concomitantly with the reduction in systemic blood pressure, but did not change LVEDP in the late phase. OPC-31260 reduced LVEDP and central venous pressure in both phases. OPC-21268 improved hemodynamics only in the early phase and OPC-31260 improved it in both phases.
Keywords: Heart failure, Myocardial infarction, Vasopressin receptor antagonist