CONFLICTING GASTRIC-INHIBITORY POLYPEPTIDE DATA - POSSIBLE CAUSES

The literature with respect to GIP is flooded with conflicting data especially with respect to its role in type 2 diabetes mellitus, obesity, type 1 diabetes mellitus and chronic pancreatitis. This review describes possible reasons for the discrepancies which include species variation of GIP, heterogeneity of molecules with different immunoreactivity and bioactivity, deterioration of immunoreactivity of standard and sample on prolonged storage and the effect of the preceding intake of type and quantity of food. The problems can be resolved by raising antibodies to synthetic human GIP and its fragments, the chemical characterization of and the raising of antibodies to immunoreactive GIP 8000, the correct storage of samples and the standard preparation of subjects prior to experimental procedures.