Behavioral sensitization following a single apomorphine pretreatment — selective effects on the dopamine release process

Wilcox, Richard E.; Severson, James A.; Woodward, John J.; Randall, Patrick K.; Vaughn, Dana M.; Riffee, William H.

doi:10.1016/0006-8993(90)90201-l

Cited by 7 publications

(10 citation statements)

References 21 publications

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“…Protein concentrations were determined using the BioRad Protein Assay (BioRad, Hercules, Calif., USA), after Bradford [1976]. Protein concentrations for frog brain homogenates were approximately 130 µg per assay tube, whereas rat striatal concentrations were approximately 20 µg per tube consistent with our previous reports [Severson and Wilcox, 1988;Vaughn et al, 1990;Wigal et al, 1990;Wilcox et al, 1988Wilcox et al, , 1990.…”

Section: Tissue Preparationsupporting

confidence: 69%

“…5). Rat values for D2 assays were within the range of published values [Seeman, 1981;Seeman and Niznik, 1988;Severson and Wilcox, 1988;Wilcox et al, 1988Wilcox et al, , 1990 (table 1). Specific binding was observed for Rana D2-like receptors ( fig.…”

Section: D2 Receptors Saturation Bindingsupporting

confidence: 56%

“…Saturation isotherms were log transformed and linearized [Scatchard, 1946], and equilibrium dissociation constants (Kd) and binding capacity (Bmax) were determined by non-linear analyses (LIGAND) [Munson and Rodbard, 1980], as previously described [Severson and Wilcox, 1988;Wilcox et al, 1988Wilcox et al, , 1990. According to standard methods for nonlinear analyses [Severson and Wilcox, 1988;Mak et al, 1996;Avalos et al, 2001] displacement assay data were first analyzed together within species to increase the precision and accuracy of binding parameter determinations.…”

Section: Discussionmentioning

confidence: 99%

“…Additionally, all four compounds exhibit significantly different affinities at mammalian D1 vs. D2 receptors. As previously described [MacRae et al, 1988;Welder et al, 1988;Wigal et al, 1990;Severson et al, 1990;Vaughn et al, 1990;Wilcox et al, 1990], each assay tube contained radioligand concentrations of 3.5 nM 3 H-SCH-23390 or 0.5 nM 3 H-spiperone. Radioligands were displaced with non-radioactive drug concentrations spanning at least 4 orders of magnitude.…”

Section: Displacement Assaysmentioning

confidence: 99%

“…We used d-butaclamol (2 µM) to define non-specific binding to both receptors. Ketanserin (150 nM) was added to all tubes to prevent potential binding to 5HT 2 receptors [Severson and Wilcox, 1988;Wilcox et al, 1988aWilcox et al, , 1990Vaughn et al, 1990]. The binding assay was initiated (1 ml final volume) by adding 100 µl of homogenate.…”

Section: Saturation Binding Assaysmentioning

confidence: 99%

See 4 more Smart Citations

Pharmacological Characterization of the D1- and D2-Like Dopamine Receptors from the Brain of the Leopard Frog, <i>Rana pipiens</i>

Chu

Wilczynski

Wilcox³

2001

Brain Behav Evol

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The pharmacological profiles of D1- and D2-like dopamine receptors were investigated for native brain receptors in the leopard frog, Rana pipiens, using direct binding assays, which characterize functional receptors rather than assess total receptor protein. We used homogenate assays of R. pipiens fore- and midbrains to determine, via saturation isotherms, that the dissociation constant, Kd, for ³H-SCH-23390 binding to the D1-like receptors was 0.29 nM, and the maximal receptor density, Bmax, was 40 fmoles/mg protein. This compares with the more than 10-fold higher density of D1 sites in rat striatum. Specific binding for the D2-like receptors was measurable using these methods with ³H-spiperone as the ligand. However, saturation of binding was not achieved. This contrasts with the > 400 fmoles/mg protein Bmax in rat striatum. Pharmacological profiles (rank order of potency of displacing drugs) for each receptor type were determined. We used non-radioactive SCH-23390, SKF-38393, sulpiride, and spiperone to displace ³H-SCH-23390 and ³H-spiperone at D1 and D2 receptors, respectively. Parallel displacement assays were performed with rat striatal controls. Results indicated that the relative rank order displacements in anuran dopamine receptors were characteristic of D1- and D2-like receptors. However, the rank orders were not identical to those in mammals. The rank order for affinity at D1-like receptors in both rats and frogs was SCH-23390 > SKF-38393 > spiperone > sulpiride. The rank order for affinity at D2-like receptors was spiperone > SCH-23390 > sulpiride > SKF-38393 in frogs, and spiperone > sulpiride > SCH-23390 > SKF-38393 in rats. SKF-38393 and spiperone had similar affinities for the ‘D1’ receptors in both species. SCH-23390 had a slightly lower affinity for the D1-like receptors in Rana, whereas sulpiride had a significantly lower affinity for Rana D1-like receptors compared to rat D1 receptors. In Rana D2-like receptors, spiperone and sulpiride were significantly less potent compared to rat. However, SCH-23390 and SKF-38393 were equally potent for the D2-like receptors in both species. The results indicate that amphibian brain dopamine receptors fall into two classes similar to the mammalian D1 and D2 subfamilies, but with binding characteristics slightly different from those typically described in mammals. This work represents the first pharmacological characterization of native brain dopaminergic receptors in an anuran amphibian. Because direct binding assays measure the initial aspect of the functional interaction between transmitter and receptor, these data provide an important complement to studies using cell expression systems.

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Section: Tissue Preparationsupporting

confidence: 69%

Section: D2 Receptors Saturation Bindingsupporting

confidence: 56%

Section: Discussionmentioning

confidence: 99%

Section: Displacement Assaysmentioning

confidence: 99%

Section: Saturation Binding Assaysmentioning

confidence: 99%

See 3 more Smart Citations

Pharmacological Characterization of the D1- and D2-Like Dopamine Receptors from the Brain of the Leopard Frog, <i>Rana pipiens</i>

Chu

Wilczynski

Wilcox³

2001

Brain Behav Evol

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Chronic treatment with the D1 receptor antagonist, SCH 23390, and the D2 receptor antagonist, raclopride, in cebus monkeys withdrawn from previous haloperidol treatment

Lublin

Gerlach²,

Peacock³

1993

Psychopharmacology

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The effects of chronic treatment with dopamine (DA) D1 and D2 receptor antagonists were evaluated in eight cebus apella monkeys with mild oral dyskinesia after previous haloperidol treatment. SCH 23390 (D1 antagonist) was given daily to investigate the direct behavioural effect during long-term treatment and the subsequent supersensitivity to DA agonists. Raclopride (D2 antagonist) was investigated for comparison. All drugs were given subcutaneously. SCH 23390 and raclopride induced dystonic syndromes, catalepsy, sedation and reduced locomotor activity. The monkeys developed marked tolerance to the dystonic effect of SCH 23390, while they showed increased sensibility to the dystonic effect of raclopride. Baseline oral dyskinesia (24 h after injection) remained unchanged during D1 antagonist treatment, while it increased during D2 antagonist treatment. SCH 23390 induced supersensitivity to the oral dyskinesia- and grooming-inducing effects of SKF 81297 (D1 agonist) after 9 weeks, while the subsequent treatment with raclopride induced supersensitivity to the reactivity- and stereotypy-inducing effects of quinpirole (D2 receptor agonist) after 3 weeks. Because of the possibility of a carry-over effect (SKF 81297-induced oral hyperkinesia and grooming), other changes in raclopride-induced behaviours cannot be ruled out. The development of tolerance to the dystonic effect of SCH 23390 and the unchanged baseline oral dyskinesia during SCH 23390 treatment indicate an advantageous profile of side effects of DA D1 receptor blockade.

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Changes in apomorphine pharmacodynamics following repeated treatment in 6-hydroxydopamine-lesioned rats

1996

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Behavioral sensitization following a single apomorphine pretreatment — selective effects on the dopamine release process

Cited by 7 publications

References 21 publications

Pharmacological Characterization of the D1- and D2-Like Dopamine Receptors from the Brain of the Leopard Frog, <i>Rana pipiens</i>

Pharmacological Characterization of the D1- and D2-Like Dopamine Receptors from the Brain of the Leopard Frog, <i>Rana pipiens</i>

Chronic treatment with the D1 receptor antagonist, SCH 23390, and the D2 receptor antagonist, raclopride, in cebus monkeys withdrawn from previous haloperidol treatment

Changes in apomorphine pharmacodynamics following repeated treatment in 6-hydroxydopamine-lesioned rats

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