择期手术／意外创伤后补充谷氨酰胺的效应

The effact of glutamine supplementation in patients following elective operation and accidental injury

The etabolic response to injury,whether a controlled electivesurgical procedure or an accidental injury,is characterized by the breakdown of skeletal muscle protein and the translocation of the amino acids to visceral organs and the wound.At these sites the substrate serves to dnhance host defenses,and support vital organ function and wound repair.Glutamine (GLN) plays a major role in this process,accounting for approximately one-third of the translocated nitrogen.From the data available,GLN supplemented intravenous nutrition in patients undergoing elective surgery improved nitrogen balance,helped correct the decreased GLN concentration found in the free intracellular skeletal muscle amino acid pool and enhanced net protein synthesis (particularly in skeletal muscel).Six rancomized blinded trials(two multicentered investigations) have reported a dereased length in hospital stay in postoperative patients receiving GLN supplementation.Following blunt trauma,GLN supplementation increased plasma concentrations,attenuated the immunosuppression commonly observed and decreased the rate of infection.Patients with burn injury have low GLN plasma and intramuscular concentrations,but turnover and synthesis rate are accelerated,yet apparently inadequate to support normal concentrations.These data suggests that GLN supplementation has important effects in catabolic surgical patients,but the exact mechanisms to explain these events remain unknown and more research is required to explain the apparent benefits of dietary GLN.