Effects of gradual coronary artery occlusion and exercise training on gene expression in swine heart.

Gradual occlusion (O) of the swine left circumflex coronary artery (LCX) with an ameroid occluder results in complete O within 3 weeks, collateral vessel development, and compensatory hypertrophy. The purpose of this investigation was to determine the independent and combined effects of O and exercise training (E) on gene expression in the swine heart. Adult Yucatan miniature swine were assigned to one of the following groups (n=6-9/group): sedentary control (S), exercise-trained (E), sedentary swine subjected to LCX occlusion (SO), and exercise-trained swine with LCX occlusion (EO).

The mTOR/p70S6K signal transduction pathway plays a role in cardiac hypertrophy and influences expression of myosin heavy chain genes in vivo.

Objective: Rapamycin inhibits p70 S6 kinase (p70(S6K)) activity and hypertrophy of cultured neonatal rat cardiac myocytes. The purpose of the present study was to determine whether rapamycin inhibits left ventricular (LV) hypertrophy in intact rats and whether it alters cardiac gene expression.

Methods: 300 g rats were subjected to aortic constriction (AC) or sham-operation (SH) and studied 2 and 3 days after surgery.