ISSN:
1432-1106
Keywords:
Dopamine
;
Autoreceptor antagonists
;
(+)-UH 232 and (+)-AJ 76
;
Nigro-striatal system
;
6-OH-DA lesion
;
Rotational behaviour
;
In vivo DP-5,6-ADTN binding
;
Receptor sensitivity
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary The in vivo dopamine (DA) receptor binding and behavioural properties of the recently characterised putative preferential DA autoreceptor antagonists (+)-AJ 76 and (+)-UH 232 were studied in rats with a unilateral 6-OH-DA lesion of the substantia nigra. The main findings were a) that (+)-UH 232 and (+)-AJ 76 per se failed to produce significant turning behaviour, b) that both agents antagonised contralateral rotation caused by the DA agonist apomorphine, including a change of the characteristic two-peak apomorphine rotation pattern into a single peak, indicating that the DA antagonist properties of (+)-UH 232 and (+)-AJ 76 are retained also at denervation-sensitised postsynaptic DA receptors and — in support of this notion — c) that (+)-UH 232 and (+)-AJ 76 were able to displace the specific in vivo binding of the DA receptor agonist DP-5,6-ADTN in the denervated as well as in the intact striata of the 6-OH-DA-lesioned animals. Interestingly, in this regard (+)-UH 232 was significantly less efficient on the lesioned as compared to the intact side. The DP-5,6-ADTN-displacing effect of (+)-AJ 76 did not, however, differ between the intact and the denervated striatum. The implications of the present findings are discussed with particular reference to DA receptor sensitivity and adaptational phenomena.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00247605
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