Distal gastrectomy and Roux-Y limb in the rat - Plasma motilin, pancreaticpolypeptide concentrations, and duodenojejunal motility

After gastrectomy, Roux-Y limb reconstruction leads to duodenojejunal motor disturbances. Because motilin and pancreatic polypeptide (PP) play a role in the regulation of digestive motility, their plasma concentrations were d etermined in rats after Roux-Y gastrectomy. Three months after a distal Rou x-Y gastrectomy, coupling of electromyographic recordings and jugular sampl es were used to perform motilin and PP radioimmunoassays during and between activity fronts (AFs) occurring in the limb and in the duodenojejunum, 20, 40, and 60 min after intragastric instillation of a standard meal (5 mi Re almentyl). Animals that underwent a simple laparotomy, animals having isola ted jejunal transection, and animals with Billroth I gastrectomy (BI group) served as control groups. After Roux-Y gastrectomy, the number of AFs in t he limb (P < 0.01) and in the duodenum (P < 0.001) was reduced compared to laparotomized rats and the BI group, but did not differ from the number in the Tr group. In the limb, AFs were incompletely propagated or were retrogr ade in 9 and 3 of 20 animals, respectively. After Roux-Y gastrectomy, motil in concentrations occurred at the same time as each duodenal AF, and as in controls, and were independent from AFs in the limb. Plasma motilin concent rations were higher after Roux-Y reconstruction than in control groups (P < 0.03), and PP level concentrations were not different. After the meal, the interruption of AFs was shorter in Roux-Y reconstruction than in laparotom ized and transected animals (P < 0.05) and than in BI group, with no signif icant difference in the latter. In all groups, plasma motilin and PP concen trations were decreased (P < 0.05) and increased (P < 0.001), respectively, after the meal compared to the interdigestive period. After Roux-Y gastrec tomy, plasma motilin and PP levels were higher (P < 0.05) and lower (P < 0. 05), respectively, compared to controls. In conclusion, AFs in the Roux-Y l imb were not associated with plasma motilin concentrations, suggesting a la ck of influence of motilin on the interdigestive motor status. The decrease in postprandial plasma PP concentrations may play a role in the shorter in terruption of AFs after a meal.