[Role of calcineurin in cardiac fibroblast proliferation stimulated by angiotensin II].

The present study was undertaken to observe the role of calcineurin (CaN) in the angiotensin II (Ang II) stimulated cardiac fibroblast proliferation. In cultured cardiac fibroblasts of neonatal rats, Ang II was used to stimulate proliferation while CaN was inhibited by CaN CsA inhibitor cyclosporin A (CsA). (3)H-TdR incorporation, activity of CaN and intracellular calcium concentration were measured. (3)H-TdR incorporation of Ang II stimulated fibroblasts was 72% higher than control (P<0.01), which was inhibited by CsA (0.1 10 micromol/L) in a dose dependent manner. Intracellular Ca(2+) level and CaN activity of Ang II stimulated fibroblasts were respectively 112% (P<0.01) and 17%(P<0.05) higher than control. It is concluded that CaN may play an important role in signal transduction of the Ang II induced cardiac fibroblast proliferation.