title: The pattern of norepinephrine release in the hypothalamic paraventricular nucleus in response to repeated peripheral nerve injury differs in the acute and chronic stage in conscious rats.
abstract: We investigated the change in norepinephrine (NE) release in the hypothalamic paraventricular nucleus (PVN) in response to ligature of the median and ulnar nerves using a brain microdialysis technique in conscious rats. Primary ligature was performed of the right median and ulnar nerves, and then repeated injury was performed on the left nerves 6 h or 3 weeks after the primary ligature. Primary ligature of the nerves produced a significant increase that peaked at a mean 330% above basal NE release in the first 20 min. The NE release after reinjury 6 h later was significantly higher (a peak of 650%) than after primary nerve injury, although that at 3 weeks was significantly lower (a peak of 280%). The present study demonstrated that peripheral nerve injury induces an elevated response of the PVN, which is an integral center of the autonomic nervous system. NE release after reinjury differed in the acute and chronic stages.
authors.affiliation: Department of Orthopaedic Surgery, Kumamoto University, School of Medicine, Honjo 1-1-1, Kumamoto 860-8556, Japan.
authors.forename: Fumio
authors.initials: F
authors.lastname: Ushijima
authors.forename: Junji
authors.initials: J
authors.lastname: Ide
authors.forename: Mitsunobu
authors.initials: M
authors.lastname: Watanabe
authors.forename: Makio
authors.initials: M
authors.lastname: Yamaga
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Takagi
mesh_terms: D000208:Acute Disease; D000818:Animals; D002908:Chronic Disease; D008026:Ligation; D008297:Male; D008475:Median Nerve / Q000293:injuries; D017551:Microdialysis; D009638:Norepinephrine / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000378:metabolism*; D059348:Peripheral Nerve Injuries; D010525:Peripheral Nerves / Q000473:pathology; D051381:Rats; D017208:Rats, Wistar; D013997:Time Factors; D014459:Ulnar Nerve / Q000293:injuries; D014851:Wakefulness
chemical_list: D009638:Norepinephrine