Characterization of D2 receptors and dopamine levels in the thalamus of the rat
- Texas A M Univ. College of Medicine, Temple (USA) Univ. of Texas, Austin (USA)
The authors kinetically characterized D2 receptors in thalami pooled from a group of Sprague-Dawley rats and then determined thalamic levels of dopamine (DA), homovanillic acid (HVA), dihydroxyphenylacetic acid (DOPAC), and norepinephrine (NE) in relation to a measure of thalamic DA D2 receptor densities in another group of rats. The equilibrium dissociation constant (kd) was estimated as 0.1 nM by three independent methods, while the Bmax for thalamic D2 receptors was found to be 6.4 fmol/mg p using {sup 3}H-spiperone as ligand and ketanserin to occlude 5HT2 binding. Kinetic constants were in agreement with previously reported kinetic data from rodent caudate-putamen. This suggests that thalamic D2 receptors are similar to D2 receptors from other brain areas. Mean thalamic levels of DA, DOPAC, and HVA concur with previous reports of a sparse distribution of thalamic DA neurons. D2 receptor densities were positively correlated with DA metabolites DOPAC and HVA, but not DA or NE. These results establish fundamental characteristics of thalamic DA neurotransmission to assist in the investigation of behavioral pharmacology of this area.
- OSTI ID:
- 5923503
- Journal Information:
- Life Sciences; (USA), Journal Name: Life Sciences; (USA) Vol. 48:19; ISSN 0024-3205; ISSN LIFSA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Autoradiography of dopamine receptors and dopamine uptake sites in the spontaneously hypertensive rat
4-( sup 125 I)iodo-(2,5-dimethoxy)phenylisopropylamine and ( sup 3 H)ketanserin labeling of 5-hydroxytryptamine2 (5HT2) receptors in mammalian cells transfected with a rat 5HT2 cDNA: Evidence for multiple states and not multiple 5HT2 receptor subtypes
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
AMINES
ANIMALS
AROMATICS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CARDIOTONICS
CARDIOVASCULAR AGENTS
CENTRAL NERVOUS SYSTEM
CHEMICAL COMPOSITION
DOPAMINE
DRUGS
HYDROGEN COMPOUNDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LIGANDS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANS
PHENOLS
POLYPHENOLS
PROTEINS
RATS
REACTION KINETICS
RECEPTORS
RODENTS
SPIPERONE
SYMPATHOMIMETICS
THALAMUS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES