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| Predicate | Object |
|---|---|
| rdf:type | |
| lifeskim:mentions | |
| pubmed:issue |
1
|
| pubmed:dateCreated |
1991-12-3
|
| pubmed:abstractText |
The elevation and clearance of extracellular potassium following a standard contusion injury was studied in the thoracic spinal cord of rats. Animals were anesthetized, paralyzed, laminectomized at T9-T11, then artificially ventilated. A 10-g rod was released 5.0 cm above the cord with the dura intact. After impact, the dura-arachnoid and pial membranes were incised to allow penetration of K(+)-selective microelectrodes. Electrodes utilized a valinomycin ionophore and were double-barreled, with tip diameters of 3-5 microns. Extracellular potassium activity ([K+]o) increased with the depth of penetration. The maximum values of [K+]o occurred at depths greater than 500 microns, and remained so with time after injury. These data indicate that a dorsal-ventral gradient of [K+]o develops in spinal cords contused from the dorsal surface, with the greatest elevation of [K+]o in the gray matter. In 8 preparations, the maximum [K+]o was 65 +/- 8 mM (mean +/- S.E.M.) at 5 +/- 1 min after injury. The [K+]o peak values decayed with a half-time of 11.0 +/- 3.4 min. Compared with data available for the injured cat spinal cord, the peak [K+]o recovered relatively rapidly. Although a simple diffusion model could account for the rapid clearance of [K+]o, the persistence of dorsal-ventral [K+]o gradients could not be explained by such a model. It is postulated that secondary injury processes contributed to the persistent [K+]o gradients.
|
| pubmed:grant | |
| pubmed:language |
eng
|
| pubmed:journal | |
| pubmed:citationSubset |
IM
|
| pubmed:chemical | |
| pubmed:status |
MEDLINE
|
| pubmed:month |
Aug
|
| pubmed:issn |
0006-8993
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| pubmed:author | |
| pubmed:issnType |
Print
|
| pubmed:day |
9
|
| pubmed:volume |
556
|
| pubmed:owner |
NLM
|
| pubmed:authorsComplete |
Y
|
| pubmed:pagination |
71-7
|
| pubmed:dateRevised |
2007-11-14
|
| pubmed:meshHeading |
pubmed-meshheading:1933355-Animals,
pubmed-meshheading:1933355-Blood Pressure,
pubmed-meshheading:1933355-Extracellular Space,
pubmed-meshheading:1933355-Female,
pubmed-meshheading:1933355-Male,
pubmed-meshheading:1933355-Microelectrodes,
pubmed-meshheading:1933355-Potassium,
pubmed-meshheading:1933355-Rats,
pubmed-meshheading:1933355-Spinal Cord,
pubmed-meshheading:1933355-Spinal Cord Injuries,
pubmed-meshheading:1933355-Time Factors
|
| pubmed:year |
1991
|
| pubmed:articleTitle |
Elevation and clearance of extracellular K+ following contusion of the rat spinal cord.
|
| pubmed:affiliation |
Department of Neurosurgery, New York University Medical Center, NY 10016.
|
| pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|