Differential effect of N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ) on (/sup 3/H)SCH23390 and (/sup numberH/)forskolin binding in rat striatum

Journal Article · Sun Jan 01 00:00:00 EST 1989 · Life Sci.; (United States)

DOI:https://doi.org/10.1016/0024-3205(89)90583-3· OSTI ID:5990893

Norman, A B; Wachendorf, T J; Sanberg, P R

The binding of (/sup 3/H)forskolin to a homogeneous population of binding sites in rat striatum was enhanced by NaF, guanine nucleotides and MgCl/sub 2/. These effects of NaF and guanylylimidodiphosphate (Gpp(NH)p) were synergistic with MgCl/sub 2/, but NaF and Gpp(NH)p together elicited no greater enhancement of (/sup 3/H)forskolin binding. These data suggest that (/sup 3/H)forskolin may label a site which is modulated by the guanine nucleotide regulatory subunit which mediates the stimulation of adenylate cyclase (N/sub S/). The D/sub 1/ dopamine receptor is known to stimulate adenylate cyclase via N/sub S/. In rat striatum, the B/sub max/ of (/sup 3/H)forskolin binding sites in the presence of MgCl/sub 2/ and NaF was approximately two fold greater than the B/sub max/ of (/sup 3/H)SCH23390-labeled D/sub 1/ dopamine receptors. Incubation of striatal homogenates with the protein modifying reagent EEDQ elicited a concentration-dependent decrease in the binding of both (/sup 3/H)SCH23390 and (/sup 3/H)forskolin, although EEDQ was approximately 14 fold more potent at inactivating the D/sub 1/ dopamine receptor. Following in vivo administration of EEDQ there was no significant effect on (/sup 3/H)forskolin binding sites using a dose of EEDQ that irreversibly inactivated greater than 90% of D/sub 1/ dopamine receptors. These data suggest that EEDQ is a suitable tool for investigating changes in the stoichiometry of receptors and their second messenger systems.

• Research Organization: Univ. of Cincinnati College of Medicine, OH (USA)
• OSTI ID: 5990893
• Journal Information: Life Sci.; (United States), Vol. 44:13
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DOPAMINE
RECEPTORS
PHOSPHOLIPIDS
BIOCHEMICAL REACTION KINETICS
QUINOLINES
BIOLOGICAL EFFECTS
BRAIN
CYCLASES
RATS
REAGENTS
STOICHIOMETRY
TRACER TECHNIQUES
TRITIUM COMPOUNDS
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZAARENES
AZINES
BODY
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
DRUGS
ENZYMES
ESTERS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPIDS
LYASES
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANIC PHOSPHORUS COMPOUNDS
ORGANS
PHENOLS
POLYPHENOLS
PROTEINS
PYRIDINES
REACTION KINETICS
RODENTS
SYMPATHOMIMETICS
VERTEBRATES
550201* - Biochemistry- Tracer Techniques