Theileal brakeinhibition ofjejunal motility after ileal fatperfusion inman

SUMMARY Thepossibility thatmalabsorbed fatpassing through thehumanileumexertsan inhibitory feedback control on jejunal motility hasbeeninvestigated in24normalsubjects by perfusing theileumwitha fatcontaining solution designed to produce ileal luminal fat concentrations similar tothoseinsteatorrhoea (30-40 mg/ml). Meantransit timesthrough a 30cm saline perfused jejunal segmentwere measured byadyedilution technique. Thirty minutes after ileal fatperfusion, mean transit times rosemarkedly to189±25minutes froma control value of7*5±0-9 minutes (n=5;p<005). This was associated with an increase involumeofthe perfused segmentwhichroseto17541±229 ml(control 976±103ml,n=5;p<005).Transit times andsegmental volumes hadreturned towards basal values 90minutes after completing the fatperfusion. Further studies showedthatileal fatperfusion produced apronounced inhibition of jejunal pressurewave activity, percentage duration ofactivity falling froma control level of 403±50% to149±28% inthehourafter ileal perfusion (p<001). Ileal fatperfusion was associated withmarkedrises inplasma enteroglucagon andneurotensin, thepeakvalues (218±37 and68±131pmol/l) beingcomparable withthoseobserved postprandially incoeliac disease. Theseobservations showtheexistence inman ofan inhibitory intestinal control mechanism, whereby ileal fatperfusion inhibits jejunal motility anddelays caudal transit ofjejunal contents.