Effects of anthopleurin-Q on myocardial hypertrophy in rats and physiologic properties of isolated atria in guinea pigs.

AIM

To study effects of anthopleurin-Q (AP-Q) on myocardial hypertrophy in rats and isolated atria in guinea pigs.

METHODS

Two myocardial hypertrophy models in rats were established, one introduced by levothyroxine, the other by stenosis of abdominal aorta. Cardiac myocytes morphometry and functional experiments were employed to investigate effects of AP-Q.

RESULTS

Low dose of AP-Q (1 microg/kg/d, ip) reduced morphologic changes of myocardial hypertrophy in both rat models. While high dose of AP-Q (10 microg/kg/d, ip) did not, and caused mild hydropic degeneration in cardiomyocytes. High concentration of AP-Q (30 nmol/L) enhanced the contractility, raised automaticity, and prolonged the functional refractory period (FRP) in isolated left atria of guinea pigs; higher concentration (100 nmol/L) triggered arrhythmia in right atria; low concentration of AP-Q (1 nmol/L)did not affect any myocardial properties above.

CONCLUSION

Low dose of AP-Q without inotropic effect can hinder the experimental myocardial hypertrophy in rats; high dose with positive inotropic effect may be responsible for its toxic reaction.