Incidence of the circadian rhythm of the excretion pattern on acetate absorption and metabolism in the rabbit hind-gut.
Acetate absorption in the hind-gut of anaesthetized rabbits was evaluated by measuring variations in the concentration of acetate in caecocolonic loops and in arterial and venous plasma. In vivo metabolism in gut and liver tissues was studied using [1-14C]acetate. Interrelations between acetate absorption and metabolism and both phases of the excretory cycle of the rabbit were examined. The disappearance rate from the caecocolonic loop was quantitatively significant. The gut tissue metabolized acetate, and the intensity of utilization varied with the segment studied; the distal position of the large intestine showed by far the highest uptake of short-chain fatty acids (SCFAs). In addition, acetate absorption, like its metabolism in the hind-gut and liver tissues, differed in intensity according to the phase of the excretory cycle, i.e., both mechanisms were enhanced during hard faeces production. Radioactivity was found in free amino acids, organic acids and sugars. Irrespective of the location in the gut and the excretion pattern, acetate was rapidly converted into glutamate and aspartate; these nutrients were subsequently diverted towards either oxidative metabolism or biosyntheses (non essential free amino acids, proteins).
Laboratoire de physiologie de la digestion et de la nutrition, Université Paul Sabatier, Toulouse, France.
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Vernay
D000085:Acetates / Q000032:analysis / Q000097:blood / Q000378:metabolism*; D000818:Animals; D002940:Circadian Rhythm; D003672:Defecation; D005232:Fatty Acids, Volatile / Q000032:analysis / Q000378:metabolism; D007420:Intestine, Large / Q000032:analysis / Q000378:metabolism*; D008099:Liver / Q000032:analysis / Q000378:metabolism; D008297:Male; D011817:Rabbits
D000085:Acetates; D005232:Fatty Acids, Volatile