Further characterization of [3H]ifenprodil binding to sigma receptors in rat brain.
This study was undertaken to examine further the pharmacology of [3H]ifenprodil binding in rat brain at 37 degrees C. [3H]Ifenprodil bound specifically to membranes (Kd = 5.09 +/- 0.30 nM; Bmax = 2.36 +/- 0.19 pmol/mg protein). [3H]Ifenprodil binding was potently inhibited by sigma ligands and inhibitors of cytochrome P-450. The levorotatory enantiomers of pentazocine and SKF 10,047 were more potent inhibitors than corresponding dextrorotatory enantiomers. Furthermore, the pharmacological profile of [3H]ifenprodil binding was highly correlated with that of sigma 2 sites, not sigma 1 sites. The results suggest that [3H]ifenprodil labels sigma 2 sites in rat brain at 37 degrees C, and that [3H]ifenprodil would be useful for studying sigma receptor subtypes.
Hashimoto
K
K
Neuroimaging and Drug Action Section, National Institute on Drug Abuse, Baltimore, MD 21224.
London
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ED
D000818:Animals; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism*; D066298:In Vitro Techniques; D008297:Male; D010880:Piperidines / Q000493:pharmacokinetics*; D051381:Rats; D011916:Rats, Inbred F344; D016194:Receptors, N-Methyl-D-Aspartate / Q000037:antagonists & inhibitors*; D017480:Receptors, sigma / Q000378:metabolism*; D013237:Stereoisomerism
D010880:Piperidines; D016194:Receptors, N-Methyl-D-Aspartate; D017480:Receptors, sigma; C010739:ifenprodil