Dose-dependent stimulatory effect of human growth hormone on the strength and collagen deposition of colonic anastomoses in the rat

The effects of treatment with four different doses of biosynthetic human growth hormone (b-hGH; 0.125 mg kg-1 d-1, 0.5 mg kg-1 d-1, 2.0 mg kg-1 d-1, 8.0 mg kg-1 d-1) on the bursting strength and collagen deposition of rat colonic anastomoses were studied. Rats receiving 2.0 mg and 8.0 mg b-hGH demonstrated increases in the pre- and postoperative body weights, and the bursting strength and hydroxyproline content of the anastomotic segments in these groups were significantly higher than controls on day 4 postoperatively. The serum levels of insulin-like growth factor I (IGF-I) were significantly higher than the controls after four days of preoperative treatment in the groups receiving 2.0 mg and 8.0 mg b-hGH, and postoperatively the IGF-I levels were significantly higher than those of the controls in the groups receiving 0.5 mg, 2.0 mg and 8.0 mg b-hGH per kg. Consequently, positive correlations were found between treatment doses of b-hGH and anastomotic defatted dry weight, hydroxyproline content and bursting strength of colonic anastomoses.