C-Peptide

C-peptide, also known as connecting peptide, is a short 31-amino-acid polypeptide that connects A to B chains of insulin in the proinsulin molecule. Different conditions with similar clinical features were distinguished by the measurement of C-peptide serum levels in the context of diabetes or hypoglycemia. In 1967, proinsulin C-peptide was first reported in relation to the discovery of the insulin biosynthesis pathway. Initially, research of C-peptide focused on its use as a marker of insulin secretion. Later, studies revealed that C-peptide is a bioactive peptide with effects on microvascular blood flow and tissue health. It has been demonstrated that C-peptide binds to the surface of a variety of cell types such as neuronal and endothelial and may be couple to G-protein receptor at nanomolar concentrations. Animal models of type 1 diabetes has shown that nerve and kidney function were improved by C-peptide administration. Additionally, C-peptide has been revealed to reduce inflammation and contribute to repairing smooth muscle cells.