| Propofol produces immobility via action in the ventral horn of the spinal cord by a GABAergic mechanism. | |
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MedLine Citation:
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PMID: 19372332 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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BACKGROUND: We investigated the actions of propofol and isoflurane on nociceptive responses of neurons in the spinal cord. METHODS: We determined nociceptive responses of lumbar neurons in the dorsal horn (<1200 microm) and ventral horn (>1200 microm) of decerebrate rats before and during propofol (1 effective dose, ED(50)) or isoflurane (1 minimum alveolar concentration) anesthesia. During recording of ventral horn neurons, we administered picrotoxin by infusion to determine whether isoflurane and propofol differed in their effects at the gamma aminobutyric acid (GABA) Type A receptors. We also determined whether decerebration altered propofol requirements to produce immobility. RESULTS: Decerebration did not affect propofol requirements. The ED(50) for propofol was 497 +/- 58 microg x kg(-1) x min(-1) in intact rats and 420 +/- 65 microg x kg(-1) x min(-1) in decerebrated rats (P > 0.05), with corresponding propofol blood concentrations of 8.1 +/- 1.1 microg/mL and 7.3 +/- 1.1 microg/mL, respectively (P > 0.05). Propofol did not significantly depress dorsal horn neurons, but isoflurane depressed the responses to 56% of control (P < 0.05). Propofol depressed ventral horn neurons to 47% of control, whereas isoflurane depressed ventral horn neurons to 20% of control. Picrotoxin significantly reversed the depressant effect of propofol on ventral horn neuronal responses (79% of control, not significantly different from control). Pic- rotoxin, however, had no effect on isoflurane's depression of ventral horn neuronal responses (26% of control). CONCLUSIONS: Propofol acts in the spinal cord to produce immobility. This depressive effect occurs in the ventral horn and is mediated mainly by GABA(A) receptors. Isoflurane also depresses neurons in the ventral horn; however, isoflurane actions at the GABA(A) receptor are either weak or overridden by other effects in the ventral horn. |
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Authors:
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Gudrun Kungys; Jongbun Kim; Steven L Jinks; Richard J Atherley; Joseph F Antognini |
Publication Detail:
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Type: Journal Article; Research Support, N.I.H., Extramural |
Journal Detail:
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Title: Anesthesia and analgesia Volume: 108 ISSN: 1526-7598 ISO Abbreviation: Anesth. Analg. Publication Date: 2009 May |
Date Detail:
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Created Date: 2009-04-17 Completed Date: 2009-04-30 Revised Date: 2011-08-09 |
Medline Journal Info:
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Nlm Unique ID: 1310650 Medline TA: Anesth Analg Country: United States |
Other Details:
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Languages: eng Pagination: 1531-7 Citation Subset: AIM; IM |
Affiliation:
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Department of Anesthesiology and Pain Medicine, University of California, Davis, California 95616, USA. |
Export Citation:
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APA/MLA Format Download EndNote Download BibTex |
| MeSH Terms | |
Descriptor/Qualifier:
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Action Potentials Anesthetics, Inhalation / administration & dosage Anesthetics, Intravenous / administration & dosage* Animals Anterior Horn Cells / drug effects*, metabolism Decerebrate State GABA Antagonists / administration & dosage Immobilization* Isoflurane / administration & dosage Male Movement / drug effects* Pain Threshold / drug effects Picrotoxin / administration & dosage Posterior Horn Cells / drug effects, metabolism Propofol / administration & dosage* Rats Rats, Sprague-Dawley Receptors, GABA-A / drug effects, metabolism gamma-Aminobutyric Acid / metabolism* |
| Grant Support | |
ID/Acronym/Agency:
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GM47818/GM/NIGMS NIH HHS; GM61283/GM/NIGMS NIH HHS; GM78167/GM/NIGMS NIH HHS; P01 GM047818-12/GM/NIGMS NIH HHS; P01 GM047818-150006/GM/NIGMS NIH HHS; R01 GM061283-04/GM/NIGMS NIH HHS; R01 GM061283-07/GM/NIGMS NIH HHS; R01 GM078167-03/GM/NIGMS NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/Anesthetics, Inhalation; 0/Anesthetics, Intravenous; 0/GABA Antagonists; 0/Receptors, GABA-A; 124-87-8/Picrotoxin; 2078-54-8/Propofol; 26675-46-7/Isoflurane; 56-12-2/gamma-Aminobutyric Acid |
| Comments/Corrections | |
Comment In:
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Anesth Analg. 2010 Feb 1;110(2):638; author reply 638
[PMID:
20081142
]
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From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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