Role of calcium-sensing receptor in apoptosis of rat cardiomyocytes induced by anoxia-reoxygenation

AIM: To observe the expression of calcium-sensing receptor (CaSR) of rat cardiomyocytes in anoxia-reoxygenation (A/R) injury and CaSR-induced changes of intracellular calcium; involvement of CaSR in apoptosis and relevant signaling transduction pathway. METHODS: The A/R injury was remodeled in vitro; CaSR, caspase 3 and caspase 9 were deteced by Western blotting. LSCM was used to observe changes of intracellular calcium during reperfusion with or without CaSR agonist. Morphological changes in different groups were observed by light microscopes. Apoptotic cells were measured by TUNEL assay. RESULTS: By LSCM, it was found that the intracellular calcium was significantly increased during reperfusion both in A/R and activator group.Severe injury was found by HE staining in the above two groups, the number of apoptotic cells was significantly increased according to TUNEL assay. The expression of CaSR，caspase 3 and caspase 9 was significantly increased in A/R group and activator group compared with control.CONCLUSION: CaSR is involved in intracellular calcium overload in A/R cardiomyocyte, which can accelerate apoptosis during A/R.