title: Antropyloroduodenal, cholecystokinin and feeding responses to pulsatile and non-pulsatile intraduodenal lipid infusion.
abstract: The contribution of the pulsatile nature of gastric emptying to small intestinal feedback mechanisms modulating antropyloroduodenal motility and appetite is unknown. On separate days, eight healthy male volunteers (18-34 years) received randomized, single-blind, intraduodenal (ID) infusions of 10% Intralipid (2 kcal min(-1)), either continuously [CID], or in a pulsatile manner [PID] (5 s on/15 s off) and 0.9% saline (control) administered continuously, each at a rate of 1.8 mL min(-1) for 3 h. During each infusion, subjective ratings of appetite were assessed and antropyloroduodenal pressures recorded with a 16-lumen manometric assembly incorporating a pyloric sleeve sensor. Plasma cholecystokinin was measured from blood collected at regular intervals throughout the infusion. At the end of each infusion the manometric assembly was removed, subjects were offered a buffet meal and the energy and macronutrient content of the meal was measured. Both ID lipid infusions stimulated isolated pyloric pressure waves (IPPWs) (P < 0.001) and basal pyloric pressure (P < 0.01) and suppressed antral (P < 0.05) and duodenal (P < 0.05) pressure waves when compared to controls; there was no difference in the effects of CID and PID lipid on antropyloroduodenal pressures. Infusions of lipid significantly increased plasma CCK concentrations (P < 0.05) compared with saline, but concentrations were not different between the two modes of lipid delivery (P > 0.05, CID vs. PID). Both intraduodenal lipid infusions decreased hunger (P < 0.05), increased fullness (P < 0.05) and reduced energy intake (P < 0.05) when compared with controls; again there was no difference between CID and PID lipid. We conclude that at the infusion rate of similar 2 kcal min(-1), the acute effects of intraduodenal lipid on antropyloroduodenal pressures, plasma CCK concentration and appetite are not modified by a pulsatile mode of lipid delivery into the duodenum.
authors.affiliation: University of Adelaide, Department of Medicine, Royal Adelaide Hospital, Adelaide, South Australia, Australia.
authors.forename: R
authors.initials: R
authors.lastname: Vozzo
authors.forename: Y-C
authors.initials: YC
authors.lastname: Su
authors.forename: R J
authors.initials: RJ
authors.lastname: Fraser
authors.forename: G A
authors.initials: GA
authors.lastname: Wittert
authors.forename: M
authors.initials: M
authors.lastname: Horowitz
authors.forename: C H
authors.initials: CH
authors.lastname: Malbert
authors.forename: A
authors.initials: A
authors.lastname: Shulkes
authors.forename: T
authors.initials: T
authors.lastname: Volombello
authors.forename: I M
authors.initials: IM
authors.lastname: Chapman
mesh_terms: D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001066:Appetite / Q000187:drug effects / Q000502:physiology; D002766:Cholecystokinin / Q000097:blood / Q000378:metabolism*; D004386:Duodenum / Q000187:drug effects* / Q000502:physiology; D004435:Eating / Q000187:drug effects* / Q000502:physiology; D005217:Fat Emulsions, Intravenous / Q000008:administration & dosage*; D005246:Feedback; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology; D006801:Humans; D007441:Intubation, Gastrointestinal / Q000379:methods; D008297:Male; D011312:Pressure; D011673:Pulsatile Flow / Q000187:drug effects / Q000502:physiology; D011706:Pyloric Antrum / Q000187:drug effects* / Q000502:physiology; D011708:Pylorus / Q000187:drug effects* / Q000502:physiology; D016037:Single-Blind Method
chemical_list: D005217:Fat Emulsions, Intravenous; D002766:Cholecystokinin