Reduced levels of globular and asymmetric forms of acetylcholinesterase in rat left ventricle with pressure overload hypertrophy.

The aim of the present work was to determine the effect of abdominal aortic stenosis on molecular forms of acetylcholinesterase (AChE) in rat heart. Pressure-overload, left ventricular hypertrophy was produced in male Sprague-Dawley rats by suprarenal abdominal aortic constriction. After two weeks the relative heart weight was increased over 20% compared to sham-surgical controls, mostly due to left ventricular enlargement. Aortic constriction reduced AChE activity per wet weight and per unit protein by 25-30% in the left ventricle and interventricular septum, but not in the other chambers. However, total AChE activity per chamber was normal in the left ventricle and interventricular septum, but was elevated in the atria. The molecular forms of AChE were separated in linear sucrose gradients and their specific activities were calculated from the resulting percent activities and total AChE activities. This data showed that although aortic constriction had no effect on ratios of the various forms, it did reduce the specific activities of globular and asymmetric forms in the left ventricle and interventricular septum. The reduced AChE activity suggests that slower rates of ACh hydrolysis occur in the left ventricle in pressure-overload hypertrophy.