Preconditioning effect of nitrate medicine on different parts of the heart and its signaling pathway

AIM: To study the preconditioning effect of nitrate medicine on different parts of the heart and its signaling pathway. METHODS: The cells from different parts of the heart (atrium, left ventricle, right ventricle, apex and the whole heart) were isolated and cultured. The cultured cells were treated with hypoxia and reperfusion, hypoxia preconditioning, 1 mmol/L L-arginine preconditioning and 5 mmol/L L-arginine preconditioning, respectively. The cell necrosis rate, cell apoptosis rate, LDH concentration in the medium, the ［Ca2+］i and PKC activity in the cells were determined. RESULTS: The result show that hypoxia and reperfusion increased the necrosis rate and apoptosis rate, enhanced the concentration of LDH in the medium and the ［Ca2+］i overload in the cells (P<0.05), but there was no difference between these groups (P>0.05). After hypoxia preconditioning and L-arginine preconditioning, these indexes decreased (P<0.05) while the PKC activity increased (P<0.05). CONCLUSION: Nitrate medicine protected the cells from different parts of the heart against hypoxia and reperfusion, and this function may achieve through the activation of PKC.