EFFECT OF REGULAR EXERCISE ON EXPRESSION OF K ATP CHANNELS IN HEART OF DIABETIC RATS

Abstract

RESULTS: After the hypoxia period, cell viability rate was 98±9%, without differing from the normoxia group (p>0.05). However, after 8 or 4 h of reoxygenation, the viability rate was reduced to 51±10% (p<0.01) and 74±10% (p<0.001), respectively. In addition, the percentage of early apoptotic cells was 36% (p<0.001) after 6 h of hypoxia/4 h of reoxygenation (H/R) as assessed by MTT assay. The viability rates in the same H/R protocol increased from 74±10% to 92±10% and 80±2% in SMand NSM-treated cells, respectively, without exhibiting differences with the normoxia group (p>0.05). Interestingly, a significantly higher viability was observed only in the cells treated with the SM compared to the non-treated cells after H/R injury (p<0.05). CONCLUSIONS: Our findings suggest that cardiomyocytes are susceptible to H/R-induced injury, while the cell death rate depends on the duration of reoxygenation. Moreover, cardiomyoblasts‘ secretome inhibits their apoptosis after H/R injury while their mechanical load ―preconditioning‖ appears to boost the anti-apoptotic effects of their secretome, implying the beneficial paracrine action of cardiac muscle cells due to mechanical loading.