Hypothermic neuroprotection of peripheral nerve of rats from ischemia–reperfusion injury: intraischemic vs. reperfusion hypothermia

• Published in: Brain research Vol. 827; no. 1; pp. 63 - 69
• Main Authors: Mitsui, Yoshiyuki, Schmelzer, James D., Zollman, Paula J., Mitsui, Manami, Kihara, Mikihiro, Low, Phillip A.
• Format: Journal Article
• Language: English
• Published: London Elsevier B.V 08.05.1999; Amsterdam Elsevier; New York, NY
• Subjects: Action Potentials - physiology; Animals; Behavior, Animal - physiology; Biological and medical sciences; Electrophysiology; Hypothermia; Hypothermia, Induced; Ischemia; Ligation; Male; Medical sciences; Muscle, Skeletal - innervation; Muscle, Skeletal - physiology; Nerve Fibers - pathology; Neurology; Neuroprotection; Peripheral nerve; Rat; Rats; Rats, Sprague-Dawley; Reperfusion Injury - therapy; Space life sciences; Tibial Nerve - blood supply; Tibial Nerve - pathology; Time Factors; Vascular diseases and vascular malformations of the nervous system; Neuroprotection; Peripheral nerve; Ischemia; Rat; Hypothermia; Nervous system diseases; Pathophysiology; Rodentia; Cardiovascular disease; Cerebral disorder; Vascular disease; Vertebrata; Experimental disease; Mammalia; Reperfusion; Animal; Central nervous system disease; Cerebrovascular disease; Brain (vertebrata); Non-programmatic
• ISSN: 0006-8993; 1872-6240
• DOI: 10.1016/S0006-8993(99)01289-5

The pathophysiology of ischemic fiber degeneration (IFD) is not known, but mechanisms involved during nerve ischemia differ from those during reperfusion. We have previously demonstrated hypothermic neuroprotection of peripheral nerve from IFD. We now evaluate the efficacy of hypothermia in the intraischemic vs. the reperfusion period, using our established model of ischemia–reperfusion injury. Intraischemic hypothermia resulted in significant recovery of all indices (behavior score, electrophysiology and histology, P<0.01 or 0.05) while hypothermia during reperfusion period showed less improvement, significant only for the histological score compared to normothermia group (IFD index, P<0.05). Once hypothermia was applied in the ischemic period, the resultant neuroprotection continued into the reperfusion period, even if nerve temperature was then raised during the reperfusion period. These results indicate that hypothermic neuroprotection is more efficacious during the intraischemic period than during reperfusion, when a lesser degree of neuroprotection ensued.