Background/aim: The growth promoting effects of GH and IGF-I are additive in uremic and healthy rats. The aim of this study was to analyze the growth-stimulating effects of GH and IGF-I against methylprednisolone (MP) administration.

Subjects/interventions: 5 groups of seven 150 g female Sprague-Dawley rats were studied for 12 days: Group A-solvent, Group B-6 mg MP/kg/day, Group C-MP+10 IU rhGH/kg/day, Group D-MP+ 4 mg rhIGF-I/kg/day, Group E-MP+ rhGH+rhIGF-I sc. Each groups was divided into 3 subgroups: sham-operated ad lib fed (C), control pair fed (P) and nephrectomized uremic(U).

Results: In all groups (C,U,P) rhGH improved length and weight gain, rhIGF-I stimulated length gain. If both peptides were given concomitantly their growth promoting effects were nearly additive (p<0.01). Neither rhGH nor rhIGF-I increased food intake, but food utilisation (weight gain/food intake) was increased by rhGH and by concomitant treatment. Histomorphometric analysis in the upper tibial metaphysis confirmed the positive effects of the hormones.

Conclusion: Both rhGH and rhIGF-I were able to stimulate growth in MP-treated rats. While the combined treatment had the maximal effect. The combination of the hormones may become a new treatment modality for the MP-induced growth retardation of pediatric renal allograft recipients.