Tests for cataglykin activity on a cyanogen bromide fragment of human growth hormone

A peptide having the reputed essential amino acid sequence to show cataglykin-like effects was prepared from human growth hormone (hGH) by cyanogen bromide cleavage and was tested in two systems in which cataglykin has effects. The peptide prolonged the depression of blood glucose concentration brought about by insulin during intravenous insulin tolerance tests in rats. However, the magnitude of the depression caused by insulin was not increased. There was no stimulation by the peptide of glucose uptake by rat hemidiaphragrams in the presence of insulin in vitro. Thus, this peptide does not duplicate the effects of cataglykin.