Angiotensin II Partly Mediates Mechanical Stress–Induced Cardiac Hypertrophy

Publisher Website
Google Scholar
Abstract
We have previously shown that mechanical stress induces activation of protein kinases and increases in specific gene expression and protein synthesis in cardiac myocytes, all of which are similar to those evoked by humoral factors such as growth factors and hormones. Many lines of evidence have suggested that angiotensin II (Ang II) plays a vital role in cardiac hypertrophy, and it has been reported that secretion of Ang II from cultured cardiac myocytes was induced by mechanical stretch. To examine the role of Ang II in mechanical stress–induced cardiac hypertrophy, we stretched neonatal rat cardiac myocytes in the absence or presence of the Ang II receptor antagonists saralasin (an antagonist of both type 1 and type 2 receptors), CV-11974 (a type 1 receptor–specific antagonist), and PD123319 (a type 2 receptor–specific antagonist). Stretching cardiac myocytes by 20% using deformable silicone dishes rapidly increased the activities of mitogen-activated protein (MAP) kinase kinase activators and ...