Cauda Equina Syndrome and Nitric Oxide Synthase
Immunoreactivity in the Spinal Cord of the Dog
J. MARŠALA, J. KAFKA1,
N. LUKÁČOVÁ, D. ČÍŽKOVÁ, M. MARŠALA2, N. KATSUBE3
Institute of Neurobiology, Slovak Academy of
Sciences, 1Department of Neurosurgery, Medical
Faculty, Šafárik University, Košice, Slovak Republic,
2Anesthesiology Research Laboratory, University of
California, San Diego, CA, U.S.A. and 3Minase
Research Institute, Ono Pharmaceutical Company, Ltd.,
Osaka, Japan
Received July 9, 2002
Accepted October 7, 2002
Summary
The development of the cauda equina syndrome in the dog and the
involvement of spinal nitric oxide synthase immunoreactivity (NOS-IR)
and catalytic nitric oxide synthase (cNOS) activity were studied
in a pain model caused by multiple cauda equina constrictions.
Increased NOS-IR was found two days post-constriction in neurons
of the deep dorsal horn and in large, mostly bipolar neurons
located in the internal basal nucleus of Cajal seen along the
medial border of the dorsal horn. Concomitantly, NOS-IR was
detected in small neurons close to the medioventral border of
the ventral horn. High NOS-IR appeared in a dense sacral
vascular body close to the Lissauer tract in S1-S3 segments.
Somatic and fiber-like NOS-IR appeared at five days
post-constriction in the Lissauer tract and in the lateral and
medial collateral pathways arising from the Lissauer tract. Both
pathways were accompanied by a dense punctate NOS immunopositive
staining. Simultaneously, the internal basal nucleus of Cajal
and neuropil of this nucleus exhibited high NOS-IR. A
significant decrease in the number of small NOS immunoreactive
somata was noted in laminae I-II of L6-S2 segments at five days
post-constriction while, at the same time, the number of NOS
immunoreactive neurons located in laminae VIII and IX was
significantly increased. Moreover, high immunopositivity in the
sacral vascular body persisted along with a highly expressed
NOS-IR staining of vessels supplying the dorsal sacral gray
commissure and dorsal horn in S1-S3 segments. cNOS activity,
based on a radioassay of compartmentalized gray and white matter
regions of lower lumbar segments and non-compartmentalized gray
and white matter of S1-S3 segments, proved to be highly variable
for both post-constriction periods.
Key
words
Cauda equina syndrome • Nitric oxide synthase • Spinal
cord • Dog
Reprint
requests
Prof. Jozef Maršala, M.D.. Institute of Neurobiology, Slovak
Academy of Sciences, Šoltésovej 4, 040 01 Košice, Slovak
Republic. E-mail:
marsala@saske.sk
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