Several amino acids have been shown to stimulate insulin release from the pancreatic β-cell (Fajans, Knopf, Floyd, Power & Conn, 1963; Fajans, Floyd, Knopf & Conn, 1967). Although the various amino acids act directly on the β-cell there is some evidence that in the normal post-prandial state synergism occurs with various alimentary factors (Jarrett, Graver & Cohen, 1969). In this respect amino acids play a similar role to glucose after ingestion of a meal. The rise in both glucose and aminoacid levels stimulates insulin release and the insulin causes an increased uptake of glucose and amino acids by the tissues. In both instances other hormonal and alimentary factors may influence the effect of the metabolite on the β-cell.
There is evidence that the secretion of insulin in response to hyperglycaemia is impaired in the newborn infant (Baird & Farquhar, 1962). Since insulin plays an important role in tissue growth it