Effect of glutamine dipeptide on hepatic regeneration in partially hepatectomized malnourished rats

Glutamine promotes hepatic regeneration in nourished (N) rats. The aim of the present study was to evaluate the effects of glutamine-enriched total parenteral nutrition (TPN) on liver regeneration in malnourished (MN) rats. Seventy-two male Wistar rats (≅270 g) were assigned to one of two groups: N and MN. Each group was then subdivided into three groups: the first underwent partial hepatectomy (PH) and received standard TPN enriched with l-alanyl- l-glutamine (Ala-Gln); the second also underwent PH and received standard TPN, but enriched with a solution containing proline and alanine (Ala-Pro); and the third underwent no surgical procedure (control group). All experimental groups received isocaloric (188 kcal · kg −1 · d −1) and isonitrogenous (1.12 g of nitrogen · kg −1 · d −1) TPN for 96 h. All animals were injected with bromodeoxyuridine 2 h before death. The hepatic regeneration index (HRI), hepatic growth percentage (HG) and hepatic morphology were analyzed. In MN rats, HRI and HG were higher with glutamine enrichment (HRI = 81 and HG = 190) than with proline-containing TPN (HRI = 66 and HG = 154; P < 0.05) and HRI was 100 times higher in animals that underwent PH than in control animals. Morphologic analysis of hepatic tissue showed no difference among the six groups. Glutamine-enriched TPN promoted growth of the remnant liver in MN rats after PH, maintained cellular proliferation in the various experimental groups after surgery, and maintained hepatic morphology of MN rats after surgery.