The physiological impact of proinsulin C-peptide

Abstract The proinsulin C-peptide fulfills an important function in the biosynthesis of insulin by facilitating the formation of the correct secondary and tertiary structure of the hormone. C-peptide and insulin are released in equimolar amounts to the circulation but C-peptide has generally been considered to be biologically inert. However, recent studies indicate that C-peptide administration to type 1 diabetes patients is accompanied by improved renal function, amelioration of autonomic dysfunction, stimulated tissue glucose utilization and augmented skin and muscle blood flow. The cellular mechanisms underlying these effects may be related to C-peptide's capacity to stimulate both Na + …

40(th) EASD Annual Meeting of the European Association for the Study of Diabetes : Munich, Germany, 5-9 September 2004

Effects of proinsulin C-peptide on nitric oxide, microvascular blood flow and erythrocyte Na+,K+-ATPase activity in diabetes mellitus type I

This study was conducted to evaluate the influence of proinsulin C-peptide on erythrocyte Na(+),K(+)-ATPase and endothelial nitric oxide synthase activities in patients with type I diabetes. In a randomized double-blind study design, ten patients with type I diabetes received intravenous infusions of either human C-peptide or physiological saline on two different occasions. C-peptide was infused at a rate of 3 pmol.min(-1).kg(-1) for 60 min, and thereafter at 10 pmol.min(-1).kg(-1) for 60 min. At baseline and after 60 and 120 min, laser Doppler flow (LDF) was measured following acetylcholine iontophoresis or mild thermal stimulation (44 degrees C), and venous blood samples were collected to…