Relationship between p38MAPK signaling pathway and calcium over-loading during oxygen-glucose deprivation and restoration in cardiomyocytes of rats

Objective To evaluate the relationship between p38mitogen-activated protein kinase (p38MAPK) signaling pathway and calcium over-loading during oxygen-glucose deprivation and restoration (OGD/R) in cardiomyocytes of rats. Methods Cardiomyocytes obtained from Sprague-Dawley rats, aged 1-3 days, were cultured and divided into 3 groups (n=27 each) using a random number table method: control group (group C), group OGD/R and p38MAPK inhibitor SB203580 group (group SB). The cells were subjected to OGD for 6 h followed by restoration of O2-glucose supply for 2 h. Cells were incubated for 1 h with 10 μmol/L SB203580 in group SB.At 2 h of restoration of O2-glucose supply, cell morphology was observed under an inverted microscope, cell viability was measured by the CCK-8 method, the release of lactate dehydrogenase (LDH) in the supernatant was determined by 2, 4-dinitrobenzene chromogenic method, intracellular calcium concentration was determined by flow cytometry, and the expression of phosphorylated p38MAPK (p-p38MAPK) and p38MAPK was detected using Western blot.The LDH release rate and p-p38MAPK/p38MAPK ratio were calculated. Results Compared with group C, the LDH release rate, intracellular calcium concentration and p-p38MAPK/p38MAPK were significantly increased, and the cell viability was markedly decreased in group OGD/R and group SB (P<0.05). Compared with OGD/R group, the LDH release rate, intracellular calcium concentration and p-p38MAPK/p38MAPK ratio were significantly decreased, the cell viability was increased (P<0.05), the cell morphology was nearly normal, and the number of cells was increased in group SB. Conclusion p38MAPK signaling pathway can mediate calcium overload after being activated and is involved in the pathophysiological mechanism of OGD/R in cardiomyocytes of rats. Key words: Myocardial reperfusion injury; p38Mitogen-activated protein kinases; Calcium