[Calcineurin signaling pathway is involved in cardiomyocyte hypertrophy mediated by calcium activators].

AIM

To investigate the effects of intracellular free calcium ([Ca2+]i) from different resources on calcineurin (CaN) dependent signaling pathway and cardiomyocyte hypertrophy.

METHODS

Angiotensin II (Ang II,10(-7) mol/L), ryanodine (RY, 10(-7) mol/L), inositol (1,4,5)-trisphosphate (IP3, 10(-7) mol/L) were applied to stimulate the [Ca2+]i, CaN activity and protein expression were measured in primary cultured cardiomyocytes from Wistar rat. [Ca2+]i was measured using Fura-2/AM fluorescent technique. The incorporation of 3H-Leucine (3H-Leu) determined the synthesis rates of protein.

RESULTS

Ang II, RY and IP3 increased [Ca2+]i, promoted CaN activity and protein expression, and 3H-Leu incorporation in cultured cardiomyocytes compared with control (P < 0.05 or P < 0.01).

CONCLUSION

Cardiomyocyte hypertrophy is associated with the changes of cellular [Ca2+]i, but not with its resources. Indicating that CaN signaling pathway play an important role in the hypertrophy of cardiomyocytes.