Arcuate nucleus of hypothalamus involved in analgesic action of l-THP.
Acta Pharmacol Sin
; 21(5): 439-44, 2000 May.
Article
in En
| MEDLINE
| ID: mdl-11324443
ABSTRACT
AIM:
To study the role of the arcuate nucleus of hypothalamus in analgesic action of l-tetrahydropalmatine (l-THP).METHODS:
The horseradish peroxidase (HRP) retrograde tracing, HRP retrograde tracing combined with immunohistochemistry, lesion of nucleus, tail-flick test, and intra-PAG injection were used in the present study.RESULTS:
HRP retrograde tracing results showed that the striatum or accumbens nucleus connect with PAG by two pathways 1) striatum or accumbens nucleus-->arcuate nucleus-->PAG; 2) striatum or accumbens nucleus-->habenula-->PAG. It was found that neurons in the arcuate nucleus projecting to PAG were mainly beta-endorphin neurons as observed by HRP retrograde tracing combined with immuno-histochemistry. After lesion of the arcuate nucleus, the analgesic action of l-THP (40 mg.kg-1, i.p.) was abolished, while lesion of the habenula had no such effect. Moreover, intra-PAG injection of naloxone (2, 3 micrograms) could markedly attenuate the analgesic action of l-THP (40 mg.kg-1, i.p.) in a dose-dependent manner.CONCLUSION:
beta-Endorphin neurons in the arcuate nucleus play an important role in the analgesic action of l-THP.
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Collection:
01-internacional
Database:
MEDLINE
Main subject:
Berberine Alkaloids
/
Arcuate Nucleus of Hypothalamus
/
Analgesics, Non-Narcotic
/
Hypothalamus
Limits:
Animals
Language:
En
Journal:
Acta Pharmacol Sin
Journal subject:
FARMACOLOGIA
Year:
2000
Document type:
Article
Affiliation country:
China