Proinsulin C-peptide constricts glomerular afferent arterioles in diabetic mice. A potential renoprotective mechanism

摘要

The renal glomerular afferent arterioles exert critical actions to control glomerular capillary pressure, thereby influencing GFR. Thus dilation of the afferent arterioles could cause glomerular hyperfiltration. Contraction, on the other hand, will reduce capillary pressure and GFR. Thus one possible mode of action for the C-peptide's renoprotective function is via the afferent arterioles.To gain further understanding of the mechanisms by which C-peptide mediates its action, it is of considerable importance to localize a site of effect and a mechanism of action. Our hypothesis was that C-peptide induces afferent arteriolar vaso-constriction. Such an action could underpin the potential renoprotective effects of this molecule. Therefore, in this study, we investigated whether intraluminally administered C-peptide causes a change in arteriolar diameter.