English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

r3H]Dopamine binds to synaptic plasma membranes from bovine caudate nucleus with an apparent dissociation constant KBp = 0.78 PM and a capacity /imax = 102 pmol mg-’ of protein. NaCl or KC1 at 100 mM causes a doubling of the binding capacity while reducing the affinity for dopamine by half. ATP at millimolar concentrations is required for binding in all of these cases, and linear Scatchard plots are obtained both in the absence and presence of salts. Binding is insensitive to low concentrations of inhibitors of synaptosomal uptake but is extremely sensitive to inhibition by reserpine, an agent believed to be specific for uptake by synaptic vesicles. The two stereoisomers of butaclamol are approximately equipotent as inhibitors of dopamine binding. At ~10 PM concentrations, neither ouabain nor inhibitors specific for the mitochondrial electron transport-linked ATPase, such as oligomycin, efrapeptin, and antimycin A, show any inhibition of binding, while orthovanadate (50 PM), dicyclohexyl carbodi-imide (50 PM), and 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole (10 PM) are all effective inhibitors. Inhibition also is observed with ammonium chloride and extremely low concentrations of carbonyl cyanide m-chlorophenyl hydrazone (50 nM) and nigericin (3 nM) plus potassium. In other systems, these three agents act as inhibitors of proton-translocating ATPases by dissipating a transmembrane proton gradient. Concentrations of vanadate, carbonyl cyanide mchlorophenyl hydrazone, and nigericin plus potassium that completely abolish ATP-dependent dopamine binding have no inhibitory effect on dopamine stimulation of adenylate cyclase measured under identical conditions, implying that the two activities are unrelated. The similarity between the properties of low affinity dopamine binding and those of uptake systems in synaptic vesicles and adrenal chromaffln granules suggests the possibility that the apparent binding reaction is, in fact, due to the transport of dopamine into vesiculated membrane fragments. Since the demonstration of dopamine-dependent adeSibley, 1979; Snyder and Goodman, 1980; Iversen et al., nylate cyclase activity in the central nervous system 1980; Creese et al., 1981). Kebabian and Calne (1979) (Kebabian et al., 1972; Brown and Makman, 1972), there proposed that Dl receptors are linked to adenylate cyhas been a great deal of interest in identifying compounds clase, while D2 receptors are not. Titeler et al. (1979) which specifically label the receptor responsible for stimhave expanded this classification by suggesting that reulation of the enzyme. This task has been complicated ceptors that exhibit high affinity for dopamine agonists by the presence of multiple receptors for dopaminergic be designated D3 receptors and that they may function agonists and antagonists (Titeler et al., 1978; Creese and as presynaptic autoreceptors (Roth, 1979). Although there is some evidence that [3H]spiperone, [3H]apomorphine, and r3H]ADTN3 bind with high affin’ This work was supported by Research Grant NS 08309 from the National Institute of Neurological and Communicative Disorders and

the journal of neuroscience/the journal of neuroscience

Low affinity, adenosine 5'-triphosphate-dependent [3H]dopamine binding in synaptic membranes from bovine caudate is unrelated to dopamine- stimulated adenylate cyclase