The effect of SMS 201-995 on meal and CCK-stimulated peptide YY release.

Somatostatin is known to inhibit the postprandial release of most gastrointestinal hormones. The aim of the present study was to evaluate the effect of an analog of somatostatin, SMS 201-995 (120 ng/kg/hr), on both meal-induced and cholecystokinin octapeptide (CCK-8, 500 ng/kg/hr)-induced peptide YY (PYY) release. Six mongrel dogs with distal ileal Thiry-Vella loops were used in this study. PYY was measured in both plasma and ileal luminal effluent. SMS 201-995 did not affect interdigestive plasma or ileal luminal PYY concentrations. CCK-8 and a fat meal both stimulated PYY release into the circulation. SMS 201-995 completely inhibited the CCK-8 and fat-stimulated circulatory release of PYY. Both CCK-8 and a mixed meal increased ileal luminal PYY recovery. SMS 201-995 inhibited CCK-8-induced, but not meal-induced, ileal luminal PYY recovery. These findings support previous studies that describe independent circulatory and ileal luminal PYY release. We conclude that both somatostatin and CCK may have a regulatory role in postprandial circulatory release of PYY.