TY - JOUR
T1 - Bile acid metabolism by fresh human colonic contents: a comparison of caecal versus faecal samples
AU - Thomas, L A
AU - Veysey, M J
AU - French, G
AU - Hylemon, P B
AU - Murphy, G M
AU - Dowling, R H
PY - 2001
Y1 - 2001
N2 - Background-Deoxycholic acid (DCA), implicated in the pathogenesis of gall stones and colorectal. cancer, is mainly formed by bacterial deconjugation (cholylglycine hydrolase (CGH)) and 7 alpha -dehydroxylation (7 alpha -dehydroxylase (7 alpha DH)) of conjugated cholic acid (CA) in the caecum/proximal colon. Despite this, most previous studies of CGH and 7 alpha -DH have been in faeces rather than in caecal contents. In bacteria, CA increases 7 alpha -DH activity by substrate-enzyme induction but little is known about CA concentrations or CA/7 alpha -DH induction in the human colon. Aims and methods-Therefore, in fresh " faeces ", and in caecal aspirates obtained during colonoscopy from 20 patients, we: (i) compared the activities of CGH and 7a-DH, (ii) measured 7 alpha -DH in patients with " low " and " high " percentages of DCA in fasting serum (less than and greater than the median), (iii) studied CA concentrations in the right and left halves of the colon, and examined the relationships between (iv) 7 alpha -DH activity and CA concentration in caecal samples (evidence of substrate-enzyme induction), and (v) 7 alpha -DH and per cent DCA in serum. Results-Although mean CGH activity in the proximal colon (18.3 (SEM 4.40) x 10(-2) U/mg protein) was comparable with that in " faeces " (16.0 (4.10) x 10(-2) U/mg protein), mean 7a-DH in the caecum. (8.54 (1.08) x 10(-4) U/mg protein) was higher (p
AB - Background-Deoxycholic acid (DCA), implicated in the pathogenesis of gall stones and colorectal. cancer, is mainly formed by bacterial deconjugation (cholylglycine hydrolase (CGH)) and 7 alpha -dehydroxylation (7 alpha -dehydroxylase (7 alpha DH)) of conjugated cholic acid (CA) in the caecum/proximal colon. Despite this, most previous studies of CGH and 7 alpha -DH have been in faeces rather than in caecal contents. In bacteria, CA increases 7 alpha -DH activity by substrate-enzyme induction but little is known about CA concentrations or CA/7 alpha -DH induction in the human colon. Aims and methods-Therefore, in fresh " faeces ", and in caecal aspirates obtained during colonoscopy from 20 patients, we: (i) compared the activities of CGH and 7a-DH, (ii) measured 7 alpha -DH in patients with " low " and " high " percentages of DCA in fasting serum (less than and greater than the median), (iii) studied CA concentrations in the right and left halves of the colon, and examined the relationships between (iv) 7 alpha -DH activity and CA concentration in caecal samples (evidence of substrate-enzyme induction), and (v) 7 alpha -DH and per cent DCA in serum. Results-Although mean CGH activity in the proximal colon (18.3 (SEM 4.40) x 10(-2) U/mg protein) was comparable with that in " faeces " (16.0 (4.10) x 10(-2) U/mg protein), mean 7a-DH in the caecum. (8.54 (1.08) x 10(-4) U/mg protein) was higher (p
UR - http://www.scopus.com/inward/record.url?scp=0035181786&partnerID=8YFLogxK
U2 - 10.1136/gut.49.6.835
DO - 10.1136/gut.49.6.835
M3 - Article
SN - 1468-3288
VL - 49
SP - 835
EP - 842
JO - Gut
JF - Gut
IS - 6
ER -
