Non-beta-cell islet abnormalities in noninsulin-dependent diabetes mellitus.

Although there are abnormalities in the function of pancreatic alpha, delta, and PP cells in NIDDM, only in the case of the glucagon-secreting alpha cells is there sufficient evidence to indicate that these abnormalities may be metabolically important. But the cause of abnormal glucagon secretion remains to be established. Studies of delta-cell secretion have been hampered by the inability to determine the source of circulating somatostatin-like immunoreactivity and the failure to distinguish between the potential molecular species being measured. Pancreatic polypeptide remains a hormone in search of a metabolic function; the main use of its measurement may be in the study of parasympathetic nervous system function in NIDDM.