Evidence for the absorption of bile acids in the proximal small intestine of normo- and hyperlipidaemic subjects (original) (raw)
Related papers
Journal of Clinical Investigation
A B S T R A C T This investigation was undertaken in order to (a) characterize the postprandial inflow of individual bile acids to the liver and (b) determine if peripheral venous bile acid levels always adequately reflect the portal venous concentration, or if saturation of hepatic bile acid uptake can occur under physiological conditions. In five patients with uncomplicated cholesterol gallstone disease, the umbilical cord was cannulated during cholecystectomy, and a catheter was left in the left portal branch for 5 to 7 d. The serum concentrations of cholic acid, chenodeoxycholic acid, and deoxycholic acid in portal venous and systemic circulation were then determined at intervals of 15 to 30 min before and after a standardized meal.
Hepatic Uptake of Bile Acids in Man
Journal of Clinical Investigation, 1982
is the recipient of a research fellowship from the Ernst Klenk Foundation. well as total bile acids were well correlated with those in portal venous serum. The results (a) give a quantitation of postprandial bile acid inflow to the liver and (b) indicate that the hepatic uptake system for bile acids in healthy man cannot be saturated during maximal inflow of endogenous bile acids. Measurement of peripheral serum bile acids can thus give important information on the status of the enterohepatic circulation. ' Abbreviations used in this paper: C, cholic acid; CD, chenodeoxycholic acid; D, deoxycholic acid.
Gut, 1977
The serum concentrations of cholic acid (C), chenodeoxycholic acid (CD), and deoxycholic acid (D) before and after a standardised meal were determined in five healthy female subjects using a highly specific and accurate gas chromatographic-mass spectrometric technique. The C level rose significantly 60 minutes after the meal, reached a peak after 90 minutes, and had returned to the original level after 150 minutes. In contrast, the serum concentrations of CD and D displayed a significant rise by 30 minutes, reached a peak after 90 minutes, but had not returned to fasting levels after 150 minutes. The serum bile acid responses after a meal suggest that there is considerable absorption of dihydroxy bile acids in the proximal small intestine in man.
Colonic absorption of unconjugated bile acids
Digestive Diseases and Sciences, 1979
Colonic absorption of three major unconjugated bile acids-cholate, chenodeoxycholate, and deoxycholate-was measured under steady-state conditions using a technique of co-Ionic perfusion in healthy volunleers. Aqueous solutions at pH 8.0 and varying in concentration from 1 mM to 10 mM were used. The rate of chenodeoxycholate absorption averaged nine times that of cholate absorption; deoxycholate absorption was somewhat less than that of chenodeoxycholate absorption, averaging six times that of cholate. At concentrations below 5 mM, the rate of absorption of bile acids was directly proportional to concentration, so that "clearance" could be calculated. Clearance values for a 1-mM solution (ml/min/colon, mean +_ SE) were: chenodeoxycholate, 9.84 +_ 1.0; deoxycholate, 7.0 +-1; and cholate, 0.82 +_ 0.10. Since absorption was proportional to concentration in the lumen, and was more rapid for the dihydroxy acids, the major mechanism of absorption was thought to be passive nonionic diffusion. Maximal rates of bile acid absorption were calculated from a l-mM solution and found to be as high as 4.2 g/day for chenodeoxycholate, 3.2 g/day for deoxycholate, and 0.5 g/day for cholate, and the rate would be still greater for more concentrated solutions. Colonic absorption may contribute significantly to conservation of the dihydroxy bile acid pool, especially in conditions of bile acid malabsorption. Bile acids secreted into the proximal intestine are conserved efficiently by active absorption in the ileum (2-5) augmented by passive absorption throughout the intestine (5-10). Previous experiments in man have quantitated passive bile acid absorption in the jejunum (8-10) and ileum (i0, 11) and have also provided evidence that bile acids can be absorbed from the colon (12, 13). To date, there
Diagnostic value of serum primary bile acids in detecting bile acid malabsorption
Gut, 1982
Serum cholic and chenodeoxycholic acid conjugates were measured in fasting conditions and after meals in 14 patients with bile acid malabsorption due to ileal resection. Mean serum fasting levels of both primary bile acids did not differ from the controls. After meals, serum cholic acid peaks were lower in patients with ileal resection than in control subjects (p<O.OO1), while chenodeoxycholic acid peaks were reduced in colectomised patients (p<OO1). In the sera from patients with ileal resection, the glycine/glycine + taurine ratio for cholic and chenodeoxycholic acid increased (p<O.OO1) from morning to evening, and glycine/glycine + taurine ratio for chenodeoxycholic acid was significantly (p<OO1) different from the controls in the sera collected in the evening. The results are consistent with the concept of a better intestinal conservation of chenyl, mainly of the glycine conjugated form, than of cholylconjugates, in patients with ileal resection; this is probably because of passive absorption in the intestine. The postprandial peaks of serum cholic acid conjugates may therefore be regarded as a test of ileal dysfunction, while peaks of chenodeoxycholic acid conjugates suggest colonic impairment.
Biliary lipid composition in idiopathic bile acid malabsorption
Gut, 1998
Background—Chronic diarrhoea is the clinical hallmark of patients presenting with idiopathic bile acid malabsorption. Its pathogenesis is unknown; colonic water secretion can be induced by dihydroxy bile acids, but it is not known whether enrichment of the bile acid pool with these bile acids occurs in such patients. Furthermore, bile acid malabsorption is known to affect biliary lipid composition, but no information is available for the idiopathic type.Aims—To verify: (a) whether diarrhoea in patients with idiopathic bile acid malabsorption is associated with enrichment of the bile acid pool with dihydroxy bile acids; and (b) whether supersaturation with cholesterol of duodenal bile occurs in such patients as a result of chronic bile acid depletion.Patients—Thirteen patients with idiopathic bile acid malabsorption diagnosed according to abnormal 75SeHCAT test and absence of other organic diseases, and 23 control subjects.Methods—Bile rich duodenal fluid was collected during intrave...
Development of active and passive transport of bile acids in rabbit intestine
Mechanisms of Ageing and Development, 1987
Previous studies have indicated that saturable, N absent in the ileum throughout most of the suckling t ileal bile acid uptake which occurs during weaning resl in functional bile acid carriers within the ileal brush 1 undertaken in weanling and adult rabbits to establish active ileal and passive jejunal and colonic uptake of 8 a range of concentrations of cholic (C), taurocholic (T(cholic (CDC), tauroehenodeoxycholic (TCDC), glychoc cholic (I)C) and taurodeoxycholic (TI)C) acid was detl TC, GC, DC and TI)C was greater in adult than in we~)rhea and mat me maturatac results primarily through an inc border membrane. This stud~ establish the effect of maturation ol bile acids. The in vitro upta (TC), glycocholic (GC), chenod¢ rchochenodeoxycholic (GCI)C), de determined. Active ileal uptake ruling animals, whereas uptaJ was similar in both groups. The relative permeability for p~ o the jejunum and colon was similar in young and adult rat area was similar in the two groups, but was greater in the i ,' weanling rabbits due to an increase in villus height, width serosal length. However, the age-associated differences in a not explained simply on the basis of these differences in • the concentration of bile acids in the intestinal lumen, q }it from weanling to adulthood does not influence the rel the jejunum or colon to bile acids, but does increase active td unconjugated cholic acid and deoxycholic acid, but not c[ 1; Aging; Bile acids; Colon; Ileum; Jejunum; Ontogeny; P~
Gut, 1994
A new model has been developed to characterise the effect of a standardised ileal exclusion on bile acid, cholesterol, and lipoprotein metabolism in humans. Twelve patients treated by colectomy and ileostomy for ulcerative colitis were studied on two occasions: firstly with a conventional ileostomy and then three months afterwards with an ileal pouch operation with an ileoanal anastomosis and a protective loop ileostomy, excluding on average 95 cm of the distal ileum. The ileostomy contents were collected during 96 hours and the excretion of bile acids and cholesterol was determined using gas chromatography-mass spectrometry.