Release of endogenous cholecystokinin in response to gastric preloads in rats on postnatal days 9-12

Release of endogenous cholecystokinin (CCK) from the small intestine by gas tric loads was investigated in rats on postnatal days 9-12 (P9-P12). After 5-6 h of deprivation, pups received 5% b.wt. loads of water, 0.9% NaCl, 20% glucose, 20% maltose, 200 mg soybean trypsin inhibitor (SBTI) in 0.9% sali ne or sham load. Plasma was collected 15 min after the loads, and the conce ntration of bioactive CCK was measured by a specific acid sensitive bioassa y. Loads of SBTI and water significantly increased plasma CCK compared to s ham loads, but loads of saline, glucose, and maltose did not. The efficacy of the water load was not demonstrated in adult rats. The results suggest t hat the previously reported reduction of intake during independent ingestio n by hypertonic preloads of glucose and maltose was not mediated by the rel ease of CCK sufficient to be detected in the plasma under these conditions. (C) 2001 Elsevier Science Inc. All rights reserved.