ENHANCED BODY GROWTH IN UREMIC RATS TREATED WITH IGF-I AND GROWTH-HORMONE IN COMBINATION

The efficacy of seven days treatment with IGF-I (1.7 mg/kg/day), growt h hormone (GH) (2 mg/kg/day), IGF+I+GH (1.7 mg/kg/day + 2 mg/kg/day) o r vehicle, in promoting growth was investigated in female Sprague-Dawl ey rats with 5/6 nephrectomies (N = 8 per group). Treatment commenced after chronic renal failure had been present for seven weeks. Signific ant increases in body weight gain were found in all groups versus cont rol, with IGF-I+GH causing the greatest response, and increased body w eight gains correlating with increased nitrogen retention. GH treatmen t alone significantly stimulated food intake. IGF-I+GH resulted in clo se to additive increases in food conversion efficiency (18.8%, 21.5% a nd 39.6% increases with IGF-I, GH and IGF-I+GH, respectively, over con trol levels) and longitudinal bone growth (39%, 37% and 67% increases with IGF-I, GH and IGF-I+GH, respectively, vs. control). Serum insulin and cholesterol levels significantly decreased with IGF-I and IGF-I+G H treatment. Creatinine clearance did not change, suggesting there wer e no effects of treatment on kidney function. Although IGF-I at the do ses used did not result in a greater anabolic response than GH, IGF-IGH caused significantly enhanced growth while reducing serum insulin a nd cholesterol levels.