The Effects Of L-Arginine And L-Name On Coronary Flow And Oxidative Stress In Isolated Rat Hearts

Abstract

AbstractThe aim of this experimental study was to assess the effects of the acute administration of L-arginine alone and in combination with L-NAME (a non-selective NO synthase inhibitor) on the coronary flow and oxidative stress markers in isolated rat hearts. The experimental study was performed on hearts isolated from Wistar albino rats (n=12, male, 8 weeks old, body mass of 180-200 g). Retrograde perfusion of the isolated preparations was performed using a modified method according to the Langendorff technique with a gradual increase in the perfusion pressure (40–120 cmH2O). The following values were measured in the collected coronary effluents: coronary flow, released nitrites (NO production marker), superoxide anion radical and the index of lipid peroxidation (measured as thiobarbiturate reactive substances). The experimental protocol was performed under controlled conditions, followed by the administration of L-arginine alone (1 mmol) and L-arginine (1 mmol) + L-NAME (30 μmol). The results indicated that L-arginine did not significantly increase the coronary flow or the release of NO, TBARS and the superoxide anion radical. These effects were partially blocked by the joint administration of L-arginine + L-NAME, which indicated their competitive effect. Hence, the results of our study do not demonstrate significant effects of L-arginine administration on the coronary flow and oxidative stress markers in isolated rat hearts.