Early changes in protein synthesis in epicardial coronary artery of pressure-overloaded heart

In anesthetized dogs, a 4-h, approximately 30% increase in blood pressure induced by constriction of the abdominal aorta brought about an increase in the total RNA content in the left anterior descending coronary artery (LADCA) and the left ventricular (LV) myocardium (9.05 +/- 1.72 and 11.06 +/- 4.68%, respectively) but not in the left circumflex coronary artery (LCCA). Under the same experimental conditions, [14C]leucine incorporation increased in LADCA and LV myocardium (45.34 +/- 13.54 and 58.07 +/- 11.91%, respectively), but not in LCCA. The data indicate an early shift in protein synthesis in LADCA and simultaneously in the myocardium during a short-term pressor event. The difference in the shift of protein synthesis in the two main branches of the left coronary artery was related to the quantitatively different deformation of the LADCA and LCCA due to different deformation of the underlying myocardium and/or of the annulus fibrosus atrioventricularis during changes in the left or right ventricle volume [M. Gerova, E. Barta, M. Stolarik, and J. Gero, Am. J. Physiol. 262 (Heart Circ. Physiol. 31): H1049-H1053, 1992]. The results support the hypothesis that the deformation and/or rate of deformation of cells in the coronary wall may trigger an increase in protein synthesis. Changes in protein synthesis in the myocardium and LADCA were found to be reversible 2 h after releasing the aortic constriction.