Selective in vivo binding of [3H]naltriben to δ-opioid receptors in mouse brain

Add time:09/01/2019    Source:sciencedirect.com

Naltriben (NTB) is a selective antagonist for the putative δ2-opioid receptor. We have determined the regional kinetics and pharmacological profile of [3H]naltriben in vivo in mouse brain. After i.v. administration to CD1 mice, [3H]naltriben uptake and retention were high in striatum, cortical regions and olfactory tubercles, and low in superior colliculi and cerebellum. Robust rank order correlation was found between [3H]naltriben uptake in discrete brain regions and prior δ-opioid receptor binding determinations in vitro and in vivo. [3H]Naltriben binding in vivo was saturable, and was blocked by the δ-opioid receptor antagonist naltrindole, but not by the μ-opioid receptor antagonist cyprodime or the κ-opioid receptor agonist (trans)-(±)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)-cyclohexyl]benzeneacetamide mesylate (U50,488H). (E)-7-Benzylidenenaltrexone (BNTX), a selective antagonist for the putative δ1-opioid receptor, was 9.6- to 12.9-fold less potent than naltriben as an inhibitor of [3H]naltriben binding. Thus, the sites labeled by [3H]naltriben in vivo may correspond to the δ2-opioid receptor subtype. Such assignment is not definitive, particularly considering the 4-fold higher brain uptake of naltriben as compared to (E)-7-benzylidenenaltrexone. Moreover, the regional distribution of [3H]naltriben in brains from CXB-7/BY (CXBK) mice, a strain that shows supraspinal δ1- but not δ2-opioid receptor agonist effects, was quite similar to that found for CD1 mice.

We also recommend Trading Suppliers and Manufacturers of NALTRIBEN MESYLATE (cas 111555-58-9). Pls Click Website Link as below: cas 111555-58-9 suppliers

Prev:2 - Poly(urethane)s
Next:Polymer nomenclature: the controversy between source-based and structure-based representations (a personal perspective))