Similar cardiovascular effects of growth hormone and insulin-like growth factor-I in rats after experimental...

Accumulating data show that growth hormone (GH) and insulin-like growth factor-I (IGF-I) have major effects on the cardiovascular system. In the present study we have directly compared GH and IGF-I in an in vivo rat model of experimental myocardial infarction. Four weeks after ligation of the left coronary artery, male rats were treated with recombinant human (rh) GH 1.1 mg/kg per day, rhIGF-I 3.0 mg/kg per day or saline s.c. for 2 weeks. Transthoracic echocardiography was performed before and after the treatment period. Both GH and IGF-I reduced total peripheral resistance (P< 0.01), end-systolic wall stress (P< 0.01) and end-systolic short-axis area (P< 0.001 and P< 0.05). GH also increased area fractional shortening (P< 0.05). Stroke volume (SV) and SV index were improved by IGF-I (P< 0.0001), and SV tended to be increased by GH (P= 0.12). In conclusion, GH and IGF-I had similar beneficial effects on systolic function and peripheral resistance after experimental myocardial infarction.