Szilvassy Z, Koltai M, Ferdinandy P, Jakab I, Lonovics J, Tarrade T, Allard M, Braquet PG. Cromakalim and cicletanine against pacing-induced myocardial ischemia in conscious rabbits.
Life Sci 1994;
54:PL125-30. [PMID:
8114606 DOI:
10.1016/0024-3205(94)00870-1]
[Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Myocardial ischemia assessed by intracavital ST-segment elevation, shortening of ventricular effective refractory period (VERP), and increase in left ventricular end-diastolic pressure (LVEDP) was provoked by ventricular overdrive pacing (VOP) in conscious rabbits. Cromakalim (10 micrograms/kg), an ATP-sensitive K+ channel opener, and cicletanine (30 mg/kg), a cGMP-phosphodiesterase inhibitor, reduced VOP-induced ST-segment elevation and LVEDP-increase. Under resting conditions, cromakalim lowered blood pressure, increased heart rate (HR), and shortened VERP, whereas cicletanine decreased HR, prolonged VERP without changing blood pressure. Co-administration of cromakalim and cicletanine additively reduced VOP-induced ST-segment elevation, shortening of VERP, and LVEDP-increase. Cicletanine did not change cromakalim-induced hypotension but abolished reflexogenic tachycardia. This suggests that VERP shortening is not a prerequisite for the anti-ischemic effect of cromakalim, and the combination of these drugs may afford a potent and safe anti-ischemic effect without affecting hypotension induced cromakalim.
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