[3H]AHN 086 acylates peripheral benzodiazepine receptors in the rat pineal gland.
AHN 086, an isothiocyanato derivative of Ro 5-4864 (4'-chlorodiazepam), inhibits radioligand binding to peripheral benzodiazepine receptors with characteristics of an irreversible (acylating) ligand. We now report that [3H]AHN 086 labels a approximately 30 kDa protein in the rat pineal gland determined by both SDS-polyacrylamide gel electrophoresis and gel filtration high-performance liquid chromatography of digitonin-solubilized membranes. Specific incorporation of [3H]AHN 086 into this protein was inhibited by preincubating membranes with excess AHN 086. Moreover, significant specific binding of [3H]AHN 086 was not observed in either bovine pineal gland (which does not possess high-affinity binding sites for Ro 5-4864) or ovalbumin. These findings suggest that the approximately 30 kDa protein labeled by [3H]AHN 086 in rat pineal gland is associated with peripheral benzodiazepine receptors in this tissue.
McCabe
R T
RT
Laboratory of Neuroscience, NIDDK, Bethesda, MD 20892.
Schoenheimer
J A
JA
Skolnick
P
P
Newman
A H
AH
Rice
K C
KC
Reig
J A
JA
Klein
D C
DC
D000215:Acylation; D000818:Animals; D001570:Benzodiazepinones / Q000378:metabolism*; D002417:Cattle; D002850:Chromatography, Gel; D004591:Electrophoresis, Polyacrylamide Gel; D008297:Male; D008970:Molecular Weight; D010870:Pineal Gland / Q000378:metabolism*; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000302:isolation & purification / Q000378:metabolism*; D014316:Tritium
D001570:Benzodiazepinones; D011963:Receptors, GABA-A; D014316:Tritium; C049442:AHN 086