Objective To investigate the effect of low-dose microcystin-LR(MC-LR)on phosphorylation of JNK1/2, P44/42, and P38 in primary cultured rat hepatocytes.
Methods Primary rat hepatocytes were isolated by collagenase perfusion method. The obtained cells were treated with 1& #215;10-9, 1& #215;10-10, 1& #215;10-11, 1& #215;10-12 mol/L MC-LR for 3, 6, 12, and 24 h, respectively, then harvested and lysed by radio immunoprecipitation assay(RIPA). The expressions of p-JNK1/2, p-P44/42, and p-P38 were detected by Western blot.
Results With the decrease in dose of MC-LR, the expressions of p-JNK1/2, p-P44/42, and p-P38 increased after 3 h and 6 h of incubation across all designed concentrations of MC-LR, and a peak was observed at 1& #215;10-10 or 1& #215;10-11 mol/L, then the effect intensity decreased with the dose reduction. After the cells exposed for 12 h, only p-P38 showed a slight rise, and no significant differences in phosphorylation expression were found between the various dose groups and the control group. No outstanding effect was observed after 24 h exposure to MC-LR.
Conclusion Low-dose of MC-LR could enhance the phosporylation of JNK1/2, P44/42, and P38, and the effect exhibits time-response relationship.
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