Abstract: Objective To investigate the effects of calpain on apoptosis protein expression of caspase-3 and caspase-12 in rat cardiomyocytes after mechanical trauma. Methods The rats were divided into control group, trauma group , and calpain inhibitor (MDL28170) treatment group (i.p, 24 mg / kg). The protein expression of caspase-3, caspase-12, calpain-1 and calpain-2 were detected by Western blot. caspase-3 and caspase-12 activity were measured by activity detection kits. The mRNA expression of calpain-1 and calpain-2 were detected by real-time PCR. Results Compared with the control group, the expression and activity of caspase-3 and caspase-12 were both increased (P <0.01), and the expression of calpain-2 increased (P <0.01). Compared with the trauma group, the expression of calpain-2, the expression and activity of caspase-3 and caspase-12 were significantly decreased (P <0.05) after intervention with inhibitor MDL28170. Conclusions Up-regulation of calpain-2 in cardiomyocytes induced by mechanical trauma may be an important reason for the increase of the expression and activity of caspase-3 and caspase-12.

Key words: mechanical trauma, caspase-3, caspase-12, calpain-1, calpain-2