Posted by raybakes on October 31, 2004, at 7:21:30
In reply to Re: Bowel toxins,enzyme peptide conversion of aminos? » raybakes, posted by Larry Hoover on October 30, 2004, at 8:12:00
Hi Lar - just looking at what enzymes are in the gut from some abstracts...
This one on sulphation..
Distribution of 2-naphthol sulphotransferase and its endogenous substrate adenosine 3'-phosphate 5'-phosphosulphate in human tissues.
Cappiello M, Franchi M, Giuliani L, Pacifici GM.
Department of General Pathology, Medical School, University of Pisa, Italy.
The activity of sulphotransferase towards 2-naphthol and the concentration of its endogenous substrate, adenosine 3'-phosphate 5'-phosphosulphate (PAPS), have been measured in five specimens of human liver, lung, and kidney, and the mucosa from the ileum and the ascending, descending and sigmoid colon. The activity of 2-naphthol sulphotransferase (mean nmol.min-1.mg-1 protein) was 1.82 (liver); 0.034 (kidney); 0.19 (lung); 0.64 (ileum); 0.47 (ascending colon); 0.50 (descending colon); 0.40 (sigmoid colon). The concentration of PAPS (mean nmol.g-1 wet tissue) was 22.6 (liver); 4.8 (kidney); 4.3 (lung); 12.8 (ileum); 8.1 (ascending colon); 7.5 (descending colon); 6.2 (sigmoid colon). The concentration of PAPS and the activity of 2-naphthol sulphotransferase were higher in the liver than in the extrahepatic tissues. There was significant difference between ileum and ascending colon, both the activity of sulphotransferase and the concentration of PAPS being higher in the former. 2-Naphthol sulphotransferase activity and the concentration of PAPS have consistent distribution patterns. Differences between the tissues studied were more marked for sulphotransferase than for its endogenous substrate.
and this one on extrahepatic cytochromes..
Human extrahepatic cytochromes P450: function in xenobiotic metabolism and tissue-selective chemical toxicity in the respiratory and gastrointestinal tracts.
Ding X, Kaminsky LS.
Wadsworth Center, New York State Department of Health, State University of New York, Albany, New York 12201, USA. xding@wadsworth.org
Cytochrome P450 (CYP) enzymes in extrahepatic tissues often play a dominant role in target tissue metabolic activation of xenobiotic compounds. They may also determine drug efficacy and influence the tissue burden of foreign chemicals or bioavailability of therapeutic agents. This review focuses on xenobiotic-metabolizing CYPs of the human respiratory and gastrointestinal tracts, including the lung, trachea, nasal respiratory and olfactory mucosa, esophagus, stomach, small intestine, and colon. Many CYPs are expressed in one or more of these organs, including CYP1A1, CYP1A2, CYP1B1, CYP2A6, CYP2A13, CYP2B6, CYP2C8, CYP2C9, CYP2C18, CYP2C19, CYP2D6, CYP2E1, CYP2F1, CYP2J2, CYP2S1, CYP3A4, CYP3A5, and CYP4B1. Of particular interest are the preferential expression of certain CYPs in the respiratory tract and the regional differences in CYP expression profile in different parts of the gastrointestinal tract. Current research activities on the characterization of CYP expression, function, and regulation in these tissues, as well as future research needs, are discussed.
Although not expressed as highly as in the liver, I still feel they are important in the proper functioning of the bowel - I have seen some references to cyp3a4 in the bowel protecting the bowel wall from bile acids.
Ray
poster:raybakes
thread:407758
URL: http://www.dr-bob.org/babble/alter/20041022/msgs/409474.html