[Determination of plasmatic C-peptide and its clinical uses].

Physiopathological basis and methodological implications of the radioimmunological estimation of plasma C-peptide, as a test of beta cell secretory activity, are reviewed. Personal results are reported concerning C-peptide assay, both in basal and stimulative conditions, in insulindependent long-and short-term diabetes. In 1 case of organic, and 2 cases of functional hyperinsulinism, the test gave useful clinical information. The method of L. Heding-Novo Research Institute, Bagsvaerd, Denmark-, with previous elimination of proinsulin and insulinantibody in patients with high values of IgG insulin binding, proved to be suitable to endocrinological routine.