Effect of intravenous amino acids on interdigestive antroduodenal motilityand small bowel transit time

Background-Patients on total parenteral nutrition have an increased risk of developing gallstones because of gall bladder hypomotility. High dose amin o acids may prevent biliary stasis by stimulating gall bladder emptying. Aims-To investigate whether intravenous amino acids also influence antroduo denal motility. Methods-Eight healthy volunteers received, on three separate occasions, int ravenous saline (control), low dose amino acids (LDA), or high dose amino a cids (HDA). Antroduodenal motility was recorded by perfusion manometry and duodenocaecal transit time (DCTT) using the lactulose breath hydrogen test. Results-DCTT was significantly prolonged during LDA and HDA treatment compa red with control. The interdigestive motor pattern was maintained and migra ting motor complex (MMC) cycle length was significantly reduced during HDA compared with control and LDA due to a significant reduction in phase II du ration. Significantly fewer phase IIIs originated in the gastric antrum dur ing LDA and HDA compared with control. Duodenal phase II motility index was significantly reduced during I-IDA, but not during LDA, compared with cont rol. Conclusions-Separate intravenous infusion of high doses of amino acids in h ealthy volunteers: (1) modulates interdigestive antroduodenal motility; (2) shortens MMC cycle length due to a reduced duration of phase II with a low er contractile incidence both in the antrum and duodenum (phase I remains u nchanged whereas the effect on phase III is diverse: in the antrum phase II I is suppressed and in the duodenum the frequency is increased); and (3) pr olongs interdigestive DCTT.