Motility of the gastrointestinal tract and gallbladder during long-term total parenteral nutrition in dogs

BACKGROUND: The motility of the gastrointestinal tract during total parenteral nutrition (TPN) remains poorly understood. The objective of this study was to determine the motility pattern not only in the gastrointestinal tract but also in the gallbladders of dogs maintained by TPN. METHODS: Central venous catheters were inserted through the external jugular vein of 5 dogs and 6 strain gauge force transducers were sewn to the stomach, small intestine, and gallbladder. Two weeks later, oral food was discontinued and motility was recorded for 24 hours after the first migrating motor complex (MMC) was confirmed in the stomach as pre-TPN. TPN was started and continued for 4 weeks, and patterns of motor activity during TPN were recorded for 24 hours at the end of each week. RESULTS: The durations of MMC in the stomach, duodenum, and gallbladder in pre-TPN were 118 +/- 3 minutes, 118 +/- 2 minutes, and 118 +/- 2 minutes, respectively, but in the first week of TPN they were 432 +/- 56 minutes, 431 +/- 56 minutes, and 386 +/- 29 minutes, respectively. TPN times were significantly longer than those of pre-TPN (corrected p < .005). The durations of MMC in jejunoileum did not alter between pre-TPN and TPN. The occurrences of phase III in the stomach, duodenum, and gallbladder in pre-TPN were 12/d, but during TPN they were reduced significantly (corrected p < .005). CONCLUSIONS: TPN did not affect the motility of the jejunoileum but did inhibit the motor activities of the stomach, duodenum, and gallbladder. The inhibition of gallbladder contraction observed during TPN may be one of the factors inducing gallbladder disease.