| First Author | Nordquist L | Year | 2008 |
| Journal | Am J Physiol Regul Integr Comp Physiol | Volume | 294 |
| Issue | 3 | Pages | R836-41 |
| PubMed ID | 18077505 | Mgi Jnum | J:131944 |
| Mgi Id | MGI:3774863 | Doi | 10.1152/ajpregu.00811.2007 |
| Citation | Nordquist L, et al. (2008) Proinsulin C-peptide constricts glomerular afferent arterioles in diabetic mice. A potential renoprotective mechanism. Am J Physiol Regul Integr Comp Physiol 294(3):R836-41 |
| abstractText | Objective: an increased glomerular filtration rate (GFR) has been postulated as a potential mechanism involved in the progression of diabetic nephropathy. Studies suggest that C-peptide exerts a renoprotective effect on diabetes. The peptide decreases hyperfiltration in patients with type 1 diabetes, as well as in diabetic animal models. In this study, we investigated whether C-peptide causes a change in arteriolar diameter. Research Design and Methods: C57-Bl mice were made diabetic by means of a single intravenous injection of alloxan 2 wk prior to the experiment. Age-matched normoglycemic mice served as controls. Afferent arterioles, intact with the glomeruli, were dissected and microperfused. The effect of luminal application of C-peptide, compared with scrambled C-peptide or vehicle, was investigated. The effect of the Rho-kinase inhibitor Y-27632 was also investigated. Results: C-peptide constricted afferent arterioles in diabetic mice by -27% compared with the control value. Normoglycemic arterioles administered C-peptide displayed a delayed and minute response (-4%). Scrambled C-peptide or vehicle administration, whether administered to hyperglycemic or normoglycemic mice, did not induce any effect. Addition of Y-27632 abolished the effect of C-peptide. Conclusion: C-peptide induces constriction of afferent arterioles in diabetic mice. This can reduce enhanced GFR and may be one of the mechanisms in the renoprotective action of C-peptide in diabetes. |
