2003年12月
Reduced expression of a novel mu-opioid receptor (MOR) subtype MOR-1B in CXBK mice: Implications of MOR-1B in the expression of MOR-mediated responses
EUROPEAN JOURNAL OF NEUROSCIENCE
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- 巻
- 18
- 号
- 12
- 開始ページ
- 3193
- 終了ページ
- 3198
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1046/j.1460-9568.2003.03052.x
- 出版者・発行元
- BLACKWELL PUBLISHING LTD
A novel mu-opioid receptor (MOR) subtype, named MOR-1B, derived from alternatively spliced variants of MOR gene, has been isolated from the rat brain. Here we found for the first time that CXBK recombinant-inbred mice display a significant reduction in the expression of MOR-1B mRNA in the brain as compared to that in their progenitor C57BL/6 mice. In contrast, the expression level of MOR-1 mRNA in the brain of CXBK mice was similar to that found in C57BL/6 mice. Furthermore, relatively lower levels of MOR-1B immunoreactivity were detected in the periaqueductal grey matter (PAG) of CXBK mice than that observed in C57BL/6 mice. To investigate further the possible changes in MOR function to activate G-proteins under the condition of a reduced MOR-1B expression, the guanosine-5'-o-(3-[S-35]thio)triphosphate ([S-35]GTPgammaS) binding assay was performed. We found that the increased level of [S-35]GTPgammaS bindings to whole brain membranes induced by a selective MOR agonist endomorphin-1 was significantly decreased in CXBK mice, indicating that CXBK strain can be classified as MOR-1B-knockdown mice. We next investigated whether intracerebroventricular (i.c.v.) pretreatment with an antisence oligodeoxynucleotide against exon 5 of MOR gene (MOR-1B) could affect the endomorphin-1-induced supraspinal antinociception. The i.c.v. pretreatment with antisence oligodeoxynucleotide against MOR-1B produced a significant reduction in the i.c.v.-administered endomorphin-1-induced antinociceptive effect. The present data provide first evidence that a lack of MOR-1B expression may, at least in part, contribute to the reduced sensitivity to MOR agonists in CXBK mice, and MOR-1B may play a potential role in the MOR-mediated supraspinal antinociception.
- リンク情報
- ID情報
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- DOI : 10.1046/j.1460-9568.2003.03052.x
- ISSN : 0953-816X
- Web of Science ID : WOS:000187406700004