Stereological study of octreotide’s (somatostatin analogue) chronic effects on the prevention of glomerular mesangial expansion in uninephrectomized diabetic rats

Background: Diabetic nephropathy is one of the causes of end stage renal diseases (ESRD). Increase of IGF-1(insulin like growth factor) and GH (growth hormone) in diabetes induce kidney lesions especially Intraglomerular mesangial expansion, glomerular sclerosis and finally nephron dysfunction. In this research, IGF-1 and GH production inhibition by octreotide and sclerosis inhibition assessed quantitatively. Materials and methods: 21 male rats (2-month ages) were uninephrectomized from left flank and then randomly divided in 3 groups (7 per group). Diabetes was induced in second and third groups by injection of alloxan tetrahydrate (120 mg/kg) subcutaneously. Five days after diabetes induction, third group received octreotide (10 μg/day) subcutaneously for 8 weeks. After 8 weeks, kidneys from all groups were removed, fixed and sliced in 1 mm thickness for stereological study. After tissue processing, sections with 5 micron thickness were prepared from each slice and stained by PAS method. Cortex volume, glomerular volume and glomerular mesangium volume were estimated by Cavalieri and point counting methods. Mean difference of variables was analyzed by Mann-Whitney statistical test at P<0.05 level using SPSS V.12.0. Results: Chronic low dose usage of octreotide in diabetic rats can prevent increase of cortex volume (67%) and glomerular mesangial expansion (53%) significantly. This treatment inhibits increase of glomerular volume by 26% which is not significant. Conclusion: Inhibition of cortex volume and mesangial expansion in octreotide treated group showed significant effects in comparison to the non-treated diabetic group. But this treatment has no significant effect on glomerular hypertrophy in diabetic rats.