In vivo determination of transport and metabolism of deoxyglucose in intestinal tissues.

Experiments were carried out on 11 anesthetized cats (Na-pentobarbital). Uptake of a glucose analogue (2-deoxy-D-glucose) by intestinal mucosa and muscularis from arterial plasma was studied in order to determine net rate of transport and phosphorylation of the material. The theoretical basis for calculating the rate constants of forward (kx1) and reverse (kx2) transport between plasma and tissue and also phosphorylation (kx3) and dephosphorylation (kx4) of 14C labeled deoxy-glucose (DG) was determined. The method can also be used for estimating tissue glucose uptake. The rate constants were found to be: kx1 = 0.669 and 0.873; kx2 = 2.285 and 4.656; kx3 = 0.057 and 0.067; kx4 = 0.091 and 0.097 [s-1] in the mucosa and muscularis, respectively. Glucose utilisation of intestinal mucosa was 2.69 and that of muscularis 2.46 mg/(min X 100 g) tissue, respectively. Arterial glucose concentration was constant during the studies, however, it showed a variation from 120 to 250 mg/100 ml of plasma from animal to animal. Tissue glucose uptake or any of the rate constants were not influenced by the plasma level over this range.