Stimulation by D-glucose of the direct conversion of arginine to citrulline in enterocytes isolated from pig jejunum.
In enterocytes isolated from pig jejunum, L-arginine is metabolized to L-citrulline either directly or indirectly through the sequence of reactions catalysed by arginase and ornithine transcarbamylase. In the presence of 5 mM D-glucose, the direct conversion of 1mM L-[guanido-14C] arginine to L-citrulline was increased more than 4 times. Isolated enterocytes exhibit a high glycolytic capacity. Furthermore, the decarboxylation of 5mM D-[1-14C] glucose was 3.6 fold higher than the decarboxylation of 5 mM D-[6-14C] glucose which suggests the presence of a pentose phosphate pathway in enterocytes. Since the production of labelled L-citrulline from L-[guanido-14C] arginine in pig enterocyte homogenates was markedly increased in the presence of NADPH, it is proposed that the direct conversion of L-arginine to L-citrulline could be stimulated by the production of NADPH from D-glucose in the pentose phosphate pathway.
Blachier
F
F
Laboratoire d'Ecologie et de Physiologie du Système Digestif, Institut National de la Recherche Agronomique, JOUY-en-JOSAS, France.
M'Rabet-Touil
H
H
Darcy-Vrillon
B
B
Posho
L
L
Duee
P H
PH
D000818:Animals; D001120:Arginine / Q000378:metabolism*; D002250:Carbon Radioisotopes; D002956:Citrulline / Q000378:metabolism*; D005947:Glucose / Q000378:metabolism / Q000494:pharmacology*; D066298:In Vitro Techniques; D007413:Intestinal Mucosa / Q000187:drug effects / Q000378:metabolism*; D007583:Jejunum / Q000187:drug effects / Q000378:metabolism*; D013552:Swine; D014508:Urea / Q000378:metabolism
D002250:Carbon Radioisotopes; D002956:Citrulline; D014508:Urea; D001120:Arginine; D005947:Glucose