Cardioprotective effects of 3-methyl-1-phenyl-2-pyrazolin-5-one (MCI-186), a novel free radical scavenger, on acute autoimmune myocarditis in rats.
BACKGROUND
Recent evidence suggests that oxidative stress may play a role in myocarditis.


OBJECTIVE
To test the hypothesis that 3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone or MCI-186), a novel free radical scavenger, protects against acute experimental autoimmune myocarditis (EAM) in rats.


METHODS
MCI-186 was administered intraperitoneally (1 mg/kg/day, 3 mg/kg/day or 10 mg/kg/day) in rats with EAM for three weeks. The results were compared with those from untreated rats with EAM.


RESULTS
MCI-186 treatment did not affect the hemodynamics of the rats, but did reduce the severity of myocarditis when the heart weight:body weight ratio and the pathological scores were compared. There were significantly fewer myocardial interleukin-1beta-positive cells in rats with EAM treated with MCI-186 (at 3 mg/kg/day and 10 mg/kg/day) than in the untreated rats with EAM.


CONCLUSIONS
MCI-186 ameliorated acute EAM in rats, suggesting that free radicals may be involved in the development of myocarditis.
Okabe
Taka-Aki
TA
Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan.
Kishimoto
Chiharu
C
Hattori
Miki
M
Nimata
Masaomi
M
Shioji
Keisuke
K
Kita
Toru
T