Protein kinase C is partly involved in c-fos protein expression of nocuously-activated neurons but may not in concomitant modulatory action through opioid receptors at the spinal level in rats / 生理学报
Acta Physiologica Sinica
;
(6): 455-460, 2004.
Article
in English
| WPRIM
| ID: wpr-352752
ABSTRACT
The present study was aimed to examine if protein kinase C (PKC) activation is necessarily involved in both the c-fos protein expression in the nocuously-activated c-fos protein-like immunoreactive (Fos-LI) neurons and the concomitant opioid receptor-mediated modulation in the dorsal horn circuitry of the spinal cord. Formalin was injected into a hindpaw of rats 5 min after the rats were pretreated with intrathecal (i.t.) administration of chelerythrine (Chel), an inhibitor of PKC, naloxone (Nal), combined administration of these two (Chel + Nal), or vehicle (n=5 in each group),respectively. By using immunocytochemical techniques, the formalin-induced Fos-LI neurons in the lumbar dorsal horn were calculated 1 h after formalin injection. The results showed that (1) i.t. Chel significantly reduced the number of Fos-LI neurons in the dorsal horn of the spinal cord on the side ipsilateral to the formalin injection, showing a decrease by 60.3% (P<0.001) as compared to that observed in the i.t.vehicle group; (2) i.t. Nal significantly increased the number of Fos-LI neurons in the ipsilateral dorsal horn, with an increase of 46.0% (P<0.01) as compared to that in the i.t.vehicle group, the highest percentage increase being found in the deeper laminae of the dorsal horn; and (3) i.t. Chel + Nal also exhibited a significant decrease in Fos-LI neurons in the ipsilateral dorsal horn as compared to i.t. Nal group, showing a reduction of 53.2%, a value similar to that in the i.t. Chel group. These results suggest that (1) PKC plays a role in the c-fos protein expression only in nearly one half of the Fos-LI neurons in the dorsal horn; and (2) PKC is possibly not involved in the concomitant modulation on the nociception mediated by micro- (and also partly delta-) opioid receptors in the spinal cord.
Full text:
Available
Index:
WPRIM (Western Pacific)
Main subject:
Pain
/
Pharmacology
/
Physiology
/
Spinal Cord
/
Protein Kinase C
/
Nociceptors
/
Immunohistochemistry
/
Random Allocation
/
Proto-Oncogene Proteins c-fos
/
Rats, Sprague-Dawley
Limits:
Animals
Language:
English
Journal:
Acta Physiologica Sinica
Year:
2004
Type:
Article
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