GLUCOSE, GALACTOSE, AND GLUTAMINE-METABOLISM IN PIG ISOLATED ENTEROCYTES DURING DEVELOPMENT

In the pig, the gastrointestinal tract grows rapidly after birth and u ndergoes a short postnatal maturation. The objective of the present wo rk was to assess the metabolic characteristics of the small intestinal mucosa during this period by investigating glucose, galactose, and gl utamine metabolism in pig isolated enterocytes. Piglets were used imme diately after birth or at various stages during suckling or postweanin g. Fed animals were taken in a postabsorptive state. The jejunoileum w as excised and perfused with an EDTA (5 mM)-containing buffer. The epi thelial cell layer was further dissociated in the presence of hyaluron idase (0.01%). The resulting cell suspension (95% absorbing enterocyte s; viability greater than 90%) was incubated with C-14-labeled substra tes to measure (CO2)-C-14 production in parallel with substrate disapp earance. The capacity to utilize glutamine was high and remained stead y during the suckling period. Glucose utilization capacity was limited at birth and increased more than 3-fold during the first week of suck ling. Such an increase was not observed in piglets kept unsuckled sinc e birth. Galactose utilization capacity remained steady during the fir st week but afterward gradually disappeared. Lactate and pyruvate prod uction through glycolysis was the major pathway accounting for glucose or galactose disappearance. A capacity for a net glucose production f rom galactose was evidenced during the first week of suckling. Thus, i solated newborn pig enterocytes exhibit specific and transient metabol ic characteristics during the first postnatal week.