INSULIN-LIKE GROWTH-FACTOR AND GROWTH-HORMONE RECEPTOR IN NEPHROTIC RATS

In an attempt to elucidate the mechanism of growth retardation in the nephrotic syndrome, specific serum and hepatic growth factors were mea sured in Sprague-Dawley rats in which nephrotic syndrome was produced by administration of puromycin (1.5 mg.100 g body wt(-1).day(-1)) for 12 days. On the 13th day, the results of these nephrotic animals were compared with those of an equal number of pair-fed and control animals : the mean dietary intake of the nephrotic group was 71% that of the c ontrol group (P < 0.001). Serum insulin-like growth factor (IGF) bindi ng protein-3 was significantly reduced(P < 0.005) in the nephrotic rat s, compared with the pair-fed and the control groups. Hepatic IGF-I mR NA in the nephrotic rats averaged 36% that of control (P < 0.001) and 46% that of the pair-fed animals (P < 0.001). Hepatic growth hormone r eceptor (GHr) mRNA in the nephrotic rats averaged 19% of that of the c ontrol (P < 0.001) and 27% of that of the pair-fed rats (P < 0.001). T hese results indicate that the growth retardation of the nephrotic rat s may be associated with the significant decrease in IGF-I mRNA and re duction in GHr mRNA.