Effects of growth hormone and insulin-like growth factor 1 (IGF-1) treatments on the nitrogen metabolism and hepatic IGF-1-messenger RNA expression in postoperative parenterally fed rats
Journal
Journal of Parenteral and Enteral Nutrition
Journal Volume
20
Journal Issue
5
Pages
325-331
Date Issued
1996
Author(s)
Inaba T.
Saito H.
Fukushima R.
Hashiguchi Y.
Inoue T.
Fukatsu K.
Muto T.
Takenaka A.
Takahashi S.-I.
Noguchi T.
Abstract
BACKGROUND: Few studies have made direct comparisons of the metabolic effects of growth hormone (GH) and insulin-like growth factor 1 (IGF-1). We have assessed the dose-dependent effects of GH and IGF-1 treatments on nitrogen metabolism, intestinal structure, and hepatic IGF-1-messenger RNA (mRNA) expression in postoperative parenterally fed rats. METHODS: Rats were maintained on total parenteral nutrition (TPN) for 3 days after gastrectomy. GH (0.4 or 0.8 IU/kg/d) or IGF-1 (1,2, or 4 mg/kg/d) was infused throughout the experimental period. Anabolic effects of GH and IGF-1 were assessed by body weight change, nitrogen excretion, and whole-body protein turnover. Organ weights, intestinal structure, plasma IGF-1 levels and hepatic IGF-1-mRNA contents were also determined. RESULTS: Both GH and IGF-1 attenuated body weight loss and nitrogen excretion and increased whole-body protein synthesis and spleen weight. These observations suggest that the anabolic effects of 1 mg/kg/d of IGF-1 were equivalent to those of 0.66 IU/kg/d of GH. IGF-1, but not GH, reduced atrophy of the intestinal mucosa. GH treatment increased hepatic IGF-1-mRNA and the plasma IGF-1 level, whereas IGF-1 treatment increased the plasma IGF-1 level with no change in the hepatic IGF-1-mRNA content. CONCLUSIONS: Administration of GH or IGF-1 attenuates catabolism after surgery. The anabolic effects of 1 mg/kg/d of IGF-1 are equivalent to those of 0.66 IU/kg/d of GH. IGF-1 reduces intestinal mucosal atrophy. GH increases hepatic IGF-1-mRNA and the plasma IGF-1 level.
Publisher
SAGE Publications Inc.
Type
journal article