Effects of alloxan-induced diabetes on somatostatin binding to cytosolic components of rabbit gastric fundic mucosa

Diabetes was induced by administration of alloxan (150 mg/Kg) to 24 h-fasted rabbits. Somatostatinlike immunoreactivity (SLI) and cytosolic binding sites for somatostatin in gastric fundic mucosa were studied using radiolabelled Tyr¹¹-somatostatin. Three months after the onset of the disease, the specific binding of somatostatin to these sites was seen to be significantly lower, due to a reduction in the number (but not the affinity) of specific somatostatin binding sites of high-affinity and a disappearance of the specific, somatostatin binding sites of low-affinity. These changes were associated with an increase in the SLI concentration in both gastric fundic mucosa and plasma.