Effects of Glutamine Supplementation on Muscle Function in a Mouse Model of Spinal Cord Injury

Abstract

Spinal cord injury (SCI) results in loss of muscle function due to the rapid breakdown of muscle contractile proteins and high incidence of inflammation that directly hinder rehabilitation. Glutamine is an amino acid that plays a critical role in muscle integrity and in reducing inflammation, however, impaired glutamine synthesis occurs under stressful conditions. Glutamine supplementation can improve clinical outcomes from acute infection to sepsis, but its effects on skeletal muscle function in the early stages after a SCI are unknown. Based on glutamine’s benefits and clinical applicability these experiments tested the hypothesis that glutamine treatment can preserve muscle mass, strength, and fatigue resistance in a mouse model of SCI. Changes in muscle mass, maximal isometric force, and fatigability will be measured 7 days after sham or spinal cord transection (ST) surgery in mice receiving either placebo or glutamine (n=3-5/group). ST significantly reduced gastrocnemius mass independent of saline or glutamine treatment. Maximal isometric force normalized to body or muscle mass was not different among groups. Fatigue resistance was reduced with ST + saline, however, glutamine supplementation prevented the loss of fatigue resistance (38±9 vs. 57±5% of max force, respectively). Preliminary results suggest that 7 days after a SCI significant reductions in muscle fatigue resistance can be reversed by glutamine supplementation. Additional studies can continue to establish the protective effects of glutamine on muscle endurance with SCI, underscoring the importance of glutamine as a therapeutic intervention to accelerate the recovery of muscle function after a SCI.