Effect of systemic inhibition of prostaglandin synthesis on muscle protein balance after trauma in the rat.

Anaesthetized rats were subjected to a single impact trauma to the medial aspect of the right hindlimb (gastrocnemius muscle), and were compared with sham-treated controls. For 3 days after injury, muscles of the traumatized limb showed a marked catabolic response. Muscle protein repletion commenced after day 3, however, this process was not complete until 21 days after injury. Muscles of the uninjured limb of the traumatized rats also showed a distinct catabolic response, compared with rats that were never injured, although this response was less in magnitude than that of the injured limb. At 3 days after trauma, augmented synthesis of prostaglandin (PG)E2 by muscles of the injured and uninjured limb provided evidence of a local and systemic inflammatory response. Inhibition of PG synthesis by the systemic administration of naproxen (6-methoxy-alpha-methyl-2-napthaleneacetic acid) significantly reduced the catabolic loss of muscle protein seen locally and peripherally to the injury site.