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Proinsulin C-peptide abrogates type-1 diabetes-induced increase of renal endothelial nitric oxide synthase in rats

Akihiro Kamikawa1, Tatsuya Ishii, Kohei Shimada

  • 1Department of Biomedical Sciences, Graduate School of Veterinary Medicine, Hokkaido University, Sapporo, Japan.

Diabetes/Metabolism Research and Reviews
|December 20, 2007
PubMed
Abstract

Insights

Proinsulin C-peptide may protect against diabetic nephropathy by reducing abnormal renal endothelial nitric oxide synthase (eNOS) expression in early type 1 diabetes.

Area of Science:

  • Endocrinology
  • Nephrology
  • Molecular Biology

Background:

  • Proinsulin C-peptide may mitigate diabetic complications, potentially via nitric oxide (NO) pathways.
  • Elevated NO and endothelial NO synthase (eNOS) in renal endothelium are implicated in diabetic nephropathy progression.

Purpose of the Study:

  • To investigate the impact of C-peptide and insulin on eNOS expression in early-stage type 1 diabetic rat kidneys.

Main Methods:

  • Type 1 diabetes induced in rats via streptozotocin.
  • Treatment with C-peptide or insulin for one week using osmotic pumps.
  • Biochemical and histological analyses of kidney tissues.

Main Results:

  • Diabetic rats exhibited hyperglycemia and significantly reduced endogenous insulin and C-peptide.
  • C-peptide and insulin treatment aided weight recovery; only insulin lowered plasma glucose.
  • Renal eNOS protein levels increased in diabetic rats but were normalized by C-peptide or insulin treatment.

Conclusions:

  • C-peptide effectively suppresses diabetes-induced increases in renal eNOS expression.
  • This suppression suggests a protective role for C-peptide in preventing diabetic nephropathy.

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