Th e 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 fl ow and oxidative stress markers in isolated rat hearts. Th e 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 modifi ed method according to the Langendorff technique
with a gradual increase in the perfusion pressure (40–120
cmH2
O). Th e following values were measured in the collected coronary effl uents: coronary fl ow, released nitrites (NO
production marker), superoxide anion radical and the index
of lipid peroxidation (measured as thiobarbiturate reactive
substances). Th e experimental protocol was performed under controlled conditions, followed by the administration
of L-arginine alone (1 mmol) and L-arginine (1 mmol) + LNAME (30 μmol). Th e results indicated that L-arginine did
not signifi cantly increase the coronary fl ow or the release of
NO, TBARS and the superoxide anion radical. Th ese eff ects
were partially blocked by the joint administration of L-arginine + L-NAME, which indicated their competitive eff ect.
Hence, the results of our study do not demonstrate signifi cant
eff ects of L-arginine administration on the coronary fl ow and
oxidative stress markers in isolated rat hearts.
