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

Accumulating data show that growth hormone (GH) and insulin-like growth fac tor-I (IGF-I) have major effects on the cardiovascular system. In the prese nt 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 c oronary artery, male rats were treated with recombinant human (rh) GH 1.1 m g/kg per day, rhIGF-I 3.0 mg/kg per day or saline s.c. for 2 weeks. Transth oracic echocardiography was performed before and after the treatment period . Both GH and IGF-I reduced total peripheral resistance (P<0.01), end-systo lic 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 unproved by IGF-I (P<0.0001), arid SV tended to be in creased by GH (P=0.12). In conclusion, GH and IGF-I had similar beneficial effects on systolic function and peripheral resistance after experimental m yocardial infarction. (C) 2001 Harcourt Publishers Ltd.