Hemodynamic Overload–Induced Activation of Myocardial Mitogen-Activated Protein Kinases In Vivo

Abstract

Mitogen-activated protein (MAP) kinases have been shown to be activated by various growth factors in cultured or isolated cardiomyocytes. However, little is known about the regulation of MAP kinases in vivo, especially in clinically important conditions, such as hypertension and senescence. In this study, we assessed mechanical overload–induced activation of myocardial MAP kinases in beating hearts from hypertensive or senescent rats. Fifteen minutes of left ventricular hemodynamic overload activated MAP kinase activity by 2.2-fold ( P P P P P P P <0.01) than that in young (6-month-old) adults. Alterations in MAP kinase may contribute to changes in hypertrophic response in these animals.