[Microinjection of endomorphin-1 in the ventrolateral periaqueductal gray induces descending inhibition of cardiac nociception by activating µ-opioid receptor in rats].
Nan Fang Yi Ke Da Xue Xue Bao
; 38(9): 1066-1070, 2018 Aug 30.
Article
em Zh
| MEDLINE
| ID: mdl-30377099
ABSTRACT
OBJECTIVE:
To observe descending inhibition of cardiac nociception induced by microinjection of endomorphin-1 (EM1) in the ventrolateral periaqueductal gray (VLPAG) in rats effect and explore the role of µ-opioid receptor in mediating this effect.METHODS:
Male SD rats were randomized into electromyography (EMG) group and c-Fos group, both of which were further divided into 5 subgroups, namely 0.9% NaCl group, bradykinin (BK) group, BK+EM1 group, BK+CTOP group, and BK+CTOP+EM1 group. Rat models of cardiac nociception were established by intrapericardial injection of BK. The changes of cardiaosomatic motor reflex induced by BK were observed by assessing EMG responses of the dorsal spinotrapezius muscle; c-Fos expression in the spinal dorsal horn at levels T3-T5 was tested.RESULTS:
Compared with 0.9% NaCl, intrapericardial BK injection induced obvious EMG activities and significantly increased c-Fos expression in the spinal dorsal horn at T3-T5 (P < 0.05). Compared with BK injection, microinjection of EM1 in the VLPAG dose-dependently inhibited EMG activities and significantly decreased c-Fos expression (P < 0.05); microinjection of CTOP in the VLPAG produced no significant effect on EMG or c-Fos expression (P > 0.05). Microinjection of CTOP obviously reversed EM1-induced inhibition of EMG activities and c-Fos expression (P < 0.05).CONCLUSIONS:
Microinjection of EM1 in the VLPAG produces descending inhibition of cardiac nociception in rats by activating µ-opioid receptor.Palavras-chave
Texto completo:
1
Coleções:
01-internacional
Temas:
Geral
Base de dados:
MEDLINE
Assunto principal:
Oligopeptídeos
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Substância Cinzenta Periaquedutal
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Receptores Opioides mu
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Nociceptividade
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Coração
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Analgésicos Opioides
Tipo de estudo:
Prognostic_studies
Limite:
Animals
Idioma:
Zh
Revista:
Nan Fang Yi Ke Da Xue Xue Bao
Ano de publicação:
2018
Tipo de documento:
Article
País de afiliação:
China