[C-peptide and its role in the physiology and chosen endocrinopathies].

C-peptide is cleaved from the proinsulin chains A and B during insulin synthesis. The views on its role in human physiology has changed in recent years. Soon after discovery of C-peptide it was believed that this protein is inactive by-product of insulin synthesis, and its role is limited to role in conformational changes of insulin and indicator of exocrine function of the pancreas. At present, it is known that C-peptide is bioactive compound, with multiple functions, and it acts probably through membrane receptor. The known physiological actions of C-peptide are related mainly to kidneys, circulatory and nervous systems function. In kidney, it changes the glomerular filtration and proteinuria. In blood vessels, C-peptide is able to act as a vasodilator. It is also able to improve the neurotransmission rate. The newest data indicates possible involvement of C-peptide in etiopathology of diabetes and polycystic ovary syndrome. The possible role of C-peptide in these disorders is very interesting and requires further studies.