Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
  • D3 receptor  (2)
  • dopamine autoreceptors  (2)
  • release  (2)
  • 1
    ISSN: 1435-1463
    Keywords: Dopamine ; release ; D 3 receptor ; locomotor activity ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary We report on the pharmacological effects of the 20 fold D 3 vs. D 2 dopamine receptor preferring compound U 99194 A. It is shown that U 99194 A increases rat locomotor activity at doses that do not increase release or utilisation of dopamine in the striatum or the nucleus accumbens significantly. The data do not support any direct agonist action of U 99194 A at dopamine receptors. It is suggested that U 99194 A can antagonise a population of postsynaptic dopamine receptors involved in the suppression of some aspects of psychomotor activity. These postsynaptic receptors presumably belong to the D 3 receptor subtype.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1435-1463
    Keywords: Dopamine ; dopamine autoreceptors ; adrenal medulla ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Previous work in this laboratory, as well as observations reported in the literature, indicate that the adrenal medulla contains dopamine (DA) receptors of the D-2 subtype, which among other things are capable of controlling the DA level in rat adrenal glands. To further characterize the DA receptors involved in the control of the adrenal DA level, the effects of 9 DA receptor agonists with various intrinsic activities were compared. After various periods of drug administration the rats were killed by decapitation and the DA content of the adrenal glands and the DOPAC content of the forebrain were measured by high-performance liquid chromatography with electrochemical detection. All the investigated DA receptors agonists caused an increase in adrenal DA level, although statistical significance was not reached in one case /(−)-HW165/. Domperidone, a DA D-2 receptor antagonist which does not readily cross the blood brain barrier, blocked the DA-elevating effects of apomorphine, quinpirole, B-HT 920 and both enantiomers of 3-PPP. For the two ergolines terguride and SDZ 208-920 the blockade by domperidone was not complete, suggesting that their effects are mediated not only through DA, but also through other receptor systems. The dose of domperidone used (3 mg/kg) had but a marginal influence on brain DOPAC levels, supporting the almost exclusively peripheral effect of this agent. Our data indicate that the DA D-2 receptors which control the DA level in the adrenal medulla in rats, have characteristics similar to, though not identical with the autoreceptors in the forebrain.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1435-1463
    Keywords: D3 receptor ; conditioned place preference ; intracranial self-stimulation ; 7-OH-DPAT ; (+)-3PPP ; rat
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Compounds showing an in vitro binding preference for the dopamine D3 receptor were tested in two models designed to assess positive reinforcement in the rat: intracranial self-stimulation (ICSS) and conditioned place preference (CPP). R-(+)-7-OH-DPAT, a D3 preferring agonist, inhibited ICSS behaviour over a wide dose range. At higher doses, a facilitation of ICSS was seen. In the CPP model, 7-OH-DPAT was inactive except at the highest dose where a significant change in preference was seen. A dose of R-(+)-7-OH-DPAT, that significantly inhibited ICSS behaviour, was combined with a dose of d-amphetamine, that significantly facilitated ICSS behaviour. Surprisingly, this resulted in a significant synergistic facilitation of the amphetamine response. The putative D3 antagonist, U99194A was inactive in the ICSS model but induced significant place preference. The present results suggest that the dopamine D3 receptor, in contrast to the D2 receptor, has an inhibitory influence on reward mechanisms.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neural transmission 103 (1996), S. 331-341 
    ISSN: 1435-1463
    Keywords: Microinjections ; dopamine D3 ; dopamine autoreceptors ; spreading depression ; multiple regression analysis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The preferential dopamine autoreceptor, and slightly D3 preferring, antagonist (+)-UH232 (cis-(+)-(1S,2R)-5-methoxy-1-methyl-2-(n-dipropylamino) tetralin) increases locomotor activity and synaptic dopamine release in the nucleus accumbens and striatum after systemic administration to the rat. As shown in this study, (+)-UH232, was unable to produce anincrease in locomotor activity measured for 60 minutes after local administration into the terminal or somato-dendritic regions of the mesolimbic dopamine pathways or into the lateral ventricle. Instead, a dose dependent decrease of spontaneous locomotor activity after local application (0.05–50.0 nmol/ side) of (+)-UH232 into the nucleus accumbens, was seen. A similar reduction in locomotor activity was produced by the classical dopamine antagonist raclopride. Analysis of the dose*time interactions on locomotor activity did, however, indicate that there is a significant dose*time interaction after local application of (+)-UH232 into the lateral ventricle and VTA. Raclopride, on the other hand, produced only a weak time dependent effect in the VTA. The potential problem of Leao's spreading depression in micro-injection experiments were considered, however, spreading depression does not seem to influence the effects of (+)-UH232 locally applied into the nucleus accumbens. In conclusion, both (+)-UH232 and raclopride produced a dose dependent decrease in spontaneous locomotor activity when examined as the total activity count over 60 minutes after local application into the N Acc.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Springer
    Journal of neural transmission 95 (1994), S. 71-74 
    ISSN: 1435-1463
    Keywords: D3 receptor ; locomotor activity ; dopamine release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The dopamine D3 preferring ligand R-(+)-7-OH-DPAT induced strong hypolocomotion in rats. Doses producing reduction of locomotion failed to affect dopamine release or synthesis rate. These data support the hypothesis that the dopamine D3 receptor is a postsynaptic receptor with an inhibitory influence on rat locomotor activity.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    ISSN: 1435-1463
    Keywords: Dopamine ; D2 ; D3 ; receptors ; antagonists ; displacement ; release
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary To establish possible functional differences between the dopamine D2 and D3 receptor we investigated the relation between the ability, for a set of nine mixed dopamine D2 and D3 receptor antagonists, to displace N, N-dipropyl-2-amino-5,6-dihydroxy tetralin (DP-5,6-ADTN) from striatal binding sites and the subsequent behavioural consequences in vivo. Dopamine D2 receptor preferring antagonists are powerful displacers of DP-5,6-ADTN from the striatum. Maximal displacement is followed by strong hypomotility. Displacement of the agonist by the D3 preferring antagonist U99194A is only partial and results in synergistic increases in locomotor activity. Superimposing haloperidol upon GBR12909 leads to a synergistic increase in striatal dialysate dopamine concentrations. This effect is absent when combining GBR12909 with the putative D3 antagonist U99194A. These data give support for the hypothesis that the dopamine D3 receptor is functionally relevant at the postsynaptic level. Here, in contrast to the D2 receptor, it is proposed to exert an inhibitory influence on psychomotor functions.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...