Neurochemical Research

, Volume 18, Issue 3, pp 285–289 | Cite as

Lack of interaction between α2 and dopamine D2-receptors in mediating their inhibitory effects on [3H]dopamine release from rat nucleus accumbens slices

  • V. A. Russell
  • M. C. L. Lamm
  • J. J. F. Taljaard
Original Articles


The α2-adrenoceptor agonist, UK14304, dose-dependently inhibited the electrically stimulated release of dopamine (DA) from rat nucleus accumbens slices. This effect was antagonized by idazoxan, confirming that it was an α2-adrenoceptor mediated effect. There was no evidence of endogenous activation of noradrenergic receptors suggesting that the α2-adrenoceptor agonist was not acting presynaptically to inhibit noradrenaline release. An in vitro superfusion technique was used to investigate wheher there was any interaction between α2-adrenoceptors and DA D2-receptors in mediating their inhibitory effects on [3H]DA release from rat nucleus accumbens slices. α2-Adrenoceptor and DA D2-receptors interact with similar second messenger systems and it was considered that they may compete for a common pool of G-proteins. The inhibitory effects of the α2-adrenoceptor agonist, UK14304, and the DA receptor agonists, quinpirole, apomorphine and pergolide were not independent. However, there was no evidence of any interaction between UK14304 and the DA D2-receptor antagonists, sulpiride or haloperidol, suggesting that the two receptors do not compete for a common pool of G-proteins in mediating their inhibitory effects on DA release.

Key Words

Dopamine release nucleus accumbens α2-adrenoceptor dopamine D2-receptor UK14304 


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Copyright information

© Plenum Publishing Corporation 1993

Authors and Affiliations

  • V. A. Russell
    • 1
  • M. C. L. Lamm
    • 1
  • J. J. F. Taljaard
    • 1
  1. 1.MRC Research Unit for the Neurochemistry of Mental Diseases, Department of Chemical PathologyUniversity of Stellenbosch, Tygerberg HospitalTygerberg(R.S.A.)

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