THE CELLULAR AND MOLECULAR RESPONSE OF CARDIAC MYOCYTES TO MECHANICAL-STRESS

External load plays a critical role in determining muscle mass and its phenotype in cardiac myocytes. Cardiac myocytes have the ability to s ense mechanical stretch and convert it into intracellular growth signa ls, which lead to hypertrophy. Mechanical stretch of cardiac myocytes in vitro causes activation of multiple second messenger systems that a re very similar to growth factor-induced cell signaling systems. Stret ch of neonatal rat cardiac myocytes stimulates a rapid secretion of an giotensin II which, together with other growth factors, mediates stret ch-induced hypertrophic responses in vitro. In this review, various ce ll signaling mechanisms initiated by mechanical stress on cardiac myoc ytes are summarized with emphasis on potential mechanosensing mechanis ms and the relationship between mechanical loading and the cardiac ren in-angiotensin system.