Objective: To study the influence of various glucose levels on the structure and function of cultured neonatal rats cardiomyocytes.
Method: Cultured neonatal ventricular cardiomyocytes were treated with various glucose levels for 5 days: control (5.5 mmol/L); high (25.5 mmol/L); intermittent high (5.5 mmol/L or 25.5 mmol/L in every 12 hours interval); high (25.5 mmol/L) + PKC inhibitor Ro-31-8220 (50 nmol/L). Then, the cell beating frequency was counted, the cardiomyocytes diameters were measured and the expressions of PKC-alpha, PKC-beta(2), p-PKC-alpha, p-PKC-beta(2), NF-kappaB and c-fos were determined by Western blot.
Results: Compared with control group, cardiomyocytes beating frequency, diameters as well as the expressions of PKC-alpha, PKC-beta(2), p-PKC-alpha, p-PKC-beta(2), NF-kappaB and c-fos were significantly increased in high glucose concentration (all P < 0.05) and intermittent high glucose treatment further amplified these changes (all P < 0.05 vs. high glucose and control groups). High glucose induced changes could be significantly attenuated with PKC inhibitor Ro-31-8220.
Conclusion: High, especially intermittent high glucose could lead to diabetic cardiomyopathy by promoting cardiac hypertrophy, increasing beating frequency via activating PKC/NF-kappaB/c-fos pathways.