Effects of cyclosporine A on angiotensin II-induced cardiomyocyte hypertrophy in neonatal rats.

The effects of cyclosporine A (CsA) on Angiontensin II (Ang II)-induced protein contents, c-fos protein levels and cytosolic Ca2+ level ([Ca2+]i) in cultured cardiomyocytes of neonatal rats were observed. Total protein contents were determined by Bradford method. The expression of c-fos protein was detected by Western blot. [Ca2+]i labeled with fluorescent probe Fluo-3/AM was measured under a laser scanning confocal microscope. The results revealed that as compared with control, the total protein contents were increased in cardiomyocytes treated with Ang II (10(-7) mol/ L), which could be inhibited by CsA in a dose-dependent manner. It was found that Ang II could increase the c-fos protein expression, which could be inhibited by CsA in a dose-dependent manner. Ang II induced the [Ca2+]i elevation in cardiomyocytes. CsA did not influence the resting intracellular Ca2+, but inhibited significantly the Ang II-induced [Ca2+]i elevation. It was concluded that CsA can suppress the Ang II-induced c-fos protein expression and [Ca2+]i elevation in single cardiomyocyte, which might play a role in the prevention of Ang II-induced cardiomyocyte hypertrophy by CsA.