Effect of lanreotide on local kidney IGF-I and renal growth in experimental diabetes in the rat.

Initial diabetic renal hypertrophy is preceded by a transient increase in kidney insulin-like growth factor I(IGF-I). In the present study streptozotocin-diabetic rats were treated with a new somatostatin analogue (lanreotide), insulin or placebo for 7 days and compared to non-diabetic control rats. Kidney IGF-I changes were examined in the renal cortex, medulla, and whole kidney homogenates. The renal cortex contained approximately 5.5 times more IGF-I than the renal medulla (p < 0.01); further, IGF-I increased transiently and more pronouncedly in the renal cortex compared to the medulla. Lanreotide treatment significantly inhibited diabetic renal and glomerular growth compared to placebo-treated diabetic rats. Further, lanreotide treatment was followed by a significantly lower medulla IGF-I by day 2, while lanreotide had no effect on cortex IGF-I accumulation. In conclusion, IGF-I accumulated transiently and was more pronounced in the real cortex compared to the renal medulla and, further, lanreotide prevented diabetic renal and glomerular growth bringing new evidence that intervention with somatostatin analogues may have a role in the prevention of experimental diabetic kidney disease.