Elsevier

Neuroscience Letters

Volume 155, Issue 2, 11 June 1993, Pages 121-124
Neuroscience Letters

Neuromedin N is a potent modulator of dopamine D2 receptor agonist binding in rat neostriatal membranes

https://doi.org/10.1016/0304-3940(93)90687-GGet rights and content

Abstract

In the concentration range of 1–10 nM, neuromedin N produced a significant concentration-related increase in the Kd values of [3H]l-(−)-N-propylnorapomorphine binding sites in rat neostriatal membranes with a peak action at 10 nM (36% increase versus the control group mean value). The Bmax values were not affected by neuromedin N. Neurotensin at 10 nM induced an increase in the Kd values, which was not affected by a threshold concentration of neuromedin N (0.1 nM). In view of the higher potency of neuromedin N versus neurotensin to modulate neostriatal D2 receptors in contrast to the higher potency of neurotensin versus neuromedin N to bind to the cloned neurotensin receptors, it seems possible that the neuromedin N activated neostriatal neurotensin receptors controlling the D2 receptors represent a distinct subtype of neurotensin receptors.

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    Permanent address: Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences, Beijing 100050, People's Republic of China.

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