MILD HYPOTHERMIA PRESERVES CONTRACTILE FUNCTION AND INHIBITS PROSTAGLANDIN E(2) RELEASE FROM METABOLICALLY STRESSED SKELETAL-MUSCLE

An in vitro model of muscle damage was used to investigate the protect ive effect of mild hypothermia in muscle injury. Rat epitrochlearis mu scles were dissected in their entirety and suspended in Krebs-Ringer s olution and DNP, a mitochondrial uncoupler, was added. PGE(2) and lact ate release and the contractile response to stimulation were measured and compared to untreated controls. Experiments were done at 37, 35, 3 3 and 27 degrees C. At 37 degrees C, DNP stimulated muscle releases la rge amounts of PGE(2) and lactate and is unable to contract. As the te mperature is reduced, there is progressive preservation of contractile force, although high lactate levels at the lowest temperatures indica te that the metabolic stress is still resent. In contrast, DNP stimula ted PGE(2) release is completely inhibited at or below 35 degrees C an d may be related to a similar protective phenomenon seen in experiment al ischemic neuronal death.