Indirect evidence for increased mechanosensitivity of jejunal secretomotor neurones in patients with idiopathic bile acid malabsorption.
OBJECTIVE
The interdigestive motor rhythm, the migrating motor complex (MMC), is accompanied by active secretion of chloride during periods of distally propagating maximal motor activity (MMC phase III). We studied the behaviour of this system in bile acid malabsorption (BAM), a relative common cause of chronic diarrhoea. We measured motor activity and transmucosal potential difference (PD, reflecting active chloride secretion), in the proximal jejunum in healthy controls (n = 18) and in a group of patients with BAM (n = 11). The phase III-generated voltage was related to the degree of BAM quantified by the (75)SeHCAT test.


METHODS
We used a multi-channel intestinal infusion system to simultaneously measure jejunal pressure and PD. Saline passing calomel half-cells was infused into the jejunum and subcutaneously. Pressure and PD were recorded in the fasting state and after a test meal.


RESULTS
In the absence of motor activity, jejunal PD was not significantly different from zero in either group. During MMC phase III, PD reached significantly higher mean and peak levels in BAM patients. The product of MMC phase III length multiplied by voltage, over 3 h, was also significantly higher in BAM patients (controls: median 307 mV x cm, range 70-398; BAM: median 511, range 274-2271, P < 0.01). This value was also significantly correlated with the degree of BAM as reflected by the (75)SeHCAT test (P < 0.05).


CONCLUSIONS
Phase III induced jejunal secretion may be upregulated in BAM patients, resulting in overload of colonic reabsorption capacity.
Institute of Medicine, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
A
A
Bajor
K-A
KA
Ung
L
L
Ohman
M
M
Simren
E A
EA
Thomas
J C
JC
Bornstein
H
H
Sjövall
D000328:Adult; D000368:Aged; D001647:Bile Acids and Salts / Q000378:metabolism*; D016022:Case-Control Studies; D002712:Chlorides / Q000378:metabolism; D002908:Chronic Disease; D003967:Diarrhea / Q000209:etiology / Q000378:metabolism / Q000503:physiopathology; D017615:Enteric Nervous System / Q000503:physiopathology; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D007583:Jejunum / Q000378:metabolism*; D008286:Malabsorption Syndromes / Q000150:complications / Q000378:metabolism / Q000503:physiopathology*; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D008564:Membrane Potentials / Q000502:physiology; D008875:Middle Aged; D016065:Myoelectric Complex, Migrating / Q000502:physiology*; D012016:Reference Values; D018709:Statistics, Nonparametric; D055815:Young Adult
D001647:Bile Acids and Salts; D002712:Chlorides