Spinal Cord Injury Disturbs Muscle Mass and Immunity

Byron's Comments:

Loss of muscle and poor glutamine status are linked to poor immunity.

Study Title:

Glutamine concentration and immune response of spinal cord-injured rats.

Study Abstract:

BACKGROUND/OBJECTIVES: Glutamine plays a key role in immune response. Spinal cord injury (SCI) leads to severe loss of muscle mass and to a high incidence of infections. This study investigated the acute effect of SCI (2 and 5 days) on the plasma glutamine and skeletal muscle concentrations and immune responses in rats.

METHODS: A total of 29 adult male Wistar rats were divided as follows: control (C; n = 5), sham-operated (S2; n = 5) and spinal cord-transected (T2; n = 7). They were killed on day 2 after surgery/transection (acute phase). Another set was sham-operated (S5; n = 5), spinal cord-transected (T5; n = 7), and killed at day 5 after surgery/transection (secondary phase). Blood was collected; the white portion of the epitrochlearis and gastrocnemius muscles and the red portion of soleus muscles were dissected to measure the glutamine concentration. Gut-associated lymphocytes and peritoneal macrophages were obtained for immune parameters measurements.

RESULTS: Glutamine concentration in the plasma, gastrocnemius, and soleus muscles in rats with SCI were significantly reduced but not in the epitrochlearis muscle in the acute (2 days) and secondary (5 days) phases. Phagocytic response was reduced in the acute phase but increased in the secondary phase in rats with SCI. Superoxide production, on the other hand, was significantly increased at days 2 and 5 after SCI, and CD8+ lymphocytes subset decreased significantly on days 2 and 5.

CONCLUSIONS: Our results showed reduction in plasma glutamine and skeletal muscle concentrations after spinal cord transection. They also suggest that SCI and glutamine reduction contribute to an alteration in immune competence.

Study Information:

Tanhoffer RA, Yamazaki RK, Nunes EA, Pchevozniki AI, Pchevozniki AM, Nogata C, Aikawa J, Bonatto SJ, Brito G, Lissa MD, Fernandes LC. Glutamine concentration and immune response of spinal cord-injured rats. Tanhoffer RA, Yamazaki RK, Nunes EA, Pchevozniki AI, Pchevozniki AM, Nogata C, Aikawa J, Bonatto SJ, Brito G, Lissa MD, Fernande 2007 September 30(2):140-6,
Department of Physiology, Laboratory of Cellular Metabolism, Universidade Federal do Parana, Centro Politecnico-Jardim das Americas, Setor de Ciencias Biologicas, Curitiba, Parana, Brazil.

Full Study:

http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pubmed&pubmedid=17591226