title: Effect of fermentable carbohydrates on volatile fatty acids, ammonia and mineral absorption in the rat caecum.
abstract: The effects of poorly digested carbohydrates in the small intestine on caecal digestion and absorption have been studied in the rat. Even in diets lacking these carbohydrates, there was a noticeable production of volatile fatty acids (VFA) in the caecum. Except for cellulose, the carbohydrates (bran, pectin, guar-gum, crude potato-starch, lactose, lactulose) favoured considerable development of the caecum and enhanced the quantities of VFA present there. On reaching the caecum, they increased ammonia absorption as a result of a higher uptake of blood urea, even if a greater part of the urea nitrogen was used in bacterial protein synthesis. Arteriovenous differences in the caecum showed a considerable absorption of various electrolytes. VFA absorption seemed to be accompanied by a release of Cl- into the caecal contents and by absorption of the main cations, Na+ being absorbed along an unfavourable gradient between the plasma and the caecal contents.
mesh_terms: D000641:Ammonia / Q000378:metabolism*; D000818:Animals; D001158:Arteries; D002432:Cecum / Q000098:blood supply / Q000378:metabolism* / Q000382:microbiology; D004040:Dietary Carbohydrates / Q000494:pharmacology*; D004573:Electrolytes / Q000097:blood / Q000378:metabolism*; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D005285:Fermentation; D007408:Intestinal Absorption / Q000187:drug effects*; D008297:Male; D051381:Rats; D014508:Urea / Q000378:metabolism; D014680:Veins
chemical_list: D004040:Dietary Carbohydrates; D004573:Electrolytes; D005232:Fatty Acids, Volatile; D000641:Ammonia; D014508:Urea