Neuroendocrine peptides in stomach and colon of an animal model for human diabetes type I.

Twelve prediabetic and 12 diabetic non-obese diabetic (NOD) mice, all females aged 22-24 weeks, were investigated. As controls, 12 BLAB/cJ Bom mice of the same age and gender as the NOD mice were used. The concentration of several neuroendocrine peptides was determined by radioimmunoassay of tissue extracts of transmural specimens of antrum and distal colon. The neuroendocrine peptides investigated were peptide YY (PYY), somatostatin, vasoactive intestinal polypeptide (VIP), neuropeptide Y (NPY), neurotensin, and galanin. In the antrum, VIP, NPY, and galanin concentrations were all significantly lower in prediabetic and diabetic NOD mice than in controls. There was no statistical difference between NOD mice and controls regarding neurotensin content. In the colon, the concentrations of PYY, somatostatin, VIP, NPY, and galanin were lower in prediabetic and diabetic NOD mice than in controls. The concentration of neurotensin in prediabetic, but not in diabetic NOD mice was lower than that of controls. The present observations support the previously reported studies on animal models for human type I diabetes that the neuroendocrine system of the gut is disturbed. It also shows that the neuroendocrine system of the stomach and large intestine is affected. The present findings may have some implications for the gastrointestinal dysfunction observed in patients with human type I diabetes.