The roles of nuclear Ca2+/CaM dependent kinases and calcineurin on the development of myocardial hypertrophy in rat / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>To evaluate whether protein phosphorylation and dephosphorylation in nuclei play roles in the development of myocardial hypertrophy, distribution of protein kinases and phosphatases in cell fractions were determined.</p><p><b>METHODS</b>The model of hypertensive rat was established by abdominal aortic constriction. Velocity and isopyknic gradient centrifugation was employed to fractionate rat myocardium to membrane, cytosol and nuclei. Enzymatic methods were employed to determine kinases and phosphatases.</p><p><b>RESULTS</b>Compare with control group, the activity of CaMK increased by 101.1% (P < 0.01) and 40.16% (P < 0.01) respectively in nuclear and membranous fractions, changed without significance in cytosolic fraction; the activity of calcineurin in nuclei increased by 43.57%, (P < 0.05), lightly changed without significance in membranous and cytosolic fractions.</p><p><b>CONCLUSION</b>Nuclear translocation of CaMK and calcineurin, might play important roles on overload-induced cardiac hypertrophy.</p>