Bio-effects of salusins on isolated rat heart and neonatal cardiomyocytes / 中国病理生理杂志

ABSTRACT

AIM: To investigate the bio-effects of salusins on rat heart and cardiomyocytes. METHODS: The cardiac function was determined by multipurpose polygraph in isolated rat heart treated with various concentrations of salusin-? or salusin-?. [ 45Ca 2+] and [3H]-Leu incorporation were determined in cultured neonatal rat cardiomyocytes with ?-liquid scintillation counter. RESULTS: 10 -12-10 -7mol/L salusin-? and salusin-? had no effects on isolated rat cardiac function. However, salusin-? and salusin-? stimulated [ 45Ca 2+] uptake and [3H]-Leu incorporation. The [ 45Ca 2+] uptake induced by salusins were inhibited by nicardipine, and were synergistically increased by endothelin-1. The [3H]-Leu incorporation induced by salusin-? and salusin-? was inhibited by nicardipine, FK506 (a special inhibitor of carcineulin), PD 98059 (inhibitor of MAPK) and chelerthine (inhibitor of PKC). The effects of salusin-? on [ 45Ca 2+] uptake was stronger than those of salusin-?. But there were no statistical difference in [3H]-Leu incorporation between salusin-? and salusin-?. CONCLUSIONS: Salusin-? and salusin-? did not affect directly cardiac function in rat hearts. But salusins improved calcium uptake and protein synthesize in neonatal rat cardiomyocytes. Those effects of salusins were related with calcium channel, carcinuelin, MAPK and PKC signal pathways. Salusins may be the regulatory factors for myocardium growth and hypertrophy.