Propofol's effects on nociceptive behavior and spinal c-fos expression after intraplantar formalin injection in mice with a mutation in the gamma-aminobutyric acid-type(A) receptor beta3 subunit.
We investigated whether propofol affected nociceptive behavior and fos-like immunoreactivity (FLI) in the lumbo-sacral spinal cord after intraplantar formalin injection in wild-type (WT) mice and in mutant mice harboring a point mutation of the gamma-aminobutyric acid type(A) receptor, which renders them resistant to propofol. Bolus injection of propofol (30 mg/kg IV) in WT mice reduced phase 1 formalin-evoked behavior over the initial 2-3 min but did not alter phase 2 behavior or spinal FLI (64 +/- 19 cells/section) compared with WT mice receiving intralipid vehicle plus intraplantar formalin (57 +/- 19 cells/section). Most FLI was restricted to superficial dorsal horn laminae ipsilateral to the formalin injection. WT mice receiving a 60-min propofol infusion were anesthetized throughout and did not display nociceptive behavior but had FLI (58 +/- 11 cells/section) that did not differ significantly from the other WT groups. Mutant mice receiving bolus injection of propofol (30 mg/kg) and intraplantar formalin were not anesthetized and exhibited nociceptive behavior. The total FLI in the spinal cord was 47 +/- 29 cells/section. These data indicate that although propofol produces anesthesia, it does not prevent the FLI that is associated with nociception, a finding consistent with propofol lacking analgesic properties.
Merrill
Austin W
AW
Section of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, California 95616, USA.
Barter
Linda S
LS
Rudolph
Uwe
U
Eger
Edmond I
EI
Antognini
Joseph F
JF
Carstens
Mirela Iodi
MI
Carstens
E
E
D000818:Animals; D005557:Formaldehyde; D007150:Immunohistochemistry; D051379:Mice; D010146:Pain / Q000188:drug therapy* / Q000378:metabolism / Q000523:psychology; D015742:Propofol / Q000494:pharmacology*; D021122:Protein Subunits; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis*; D011963:Receptors, GABA-A / Q000187:drug effects / Q000235:genetics / Q000502:physiology*; D013116:Spinal Cord / Q000737:chemistry*
D021122:Protein Subunits; D016760:Proto-Oncogene Proteins c-fos; D011963:Receptors, GABA-A; D005557:Formaldehyde; D015742:Propofol