ISSN:
1471-4159
Quelle:
Blackwell Publishing Journal Backfiles 1879-2005
Thema:
Medizin
Notizen:
Abstract: The effect of dopamine (DA) on the binding of [3H]phorbol 12,13-dibutyrate ([3H]PdBu) in cultured rat striatal cells was examined. DA maximally increased specific [3H]PdBu binding by 70 ± 10%, an increase comparable to that observed with norepinephrine (NE). This finding suggests that DA activates protein kinase C in cultured striatal cells, because increases in [3H]PdBu binding reflect translocation of protein kinase C. Half-maximal stimulation was observed with 10–6M DA. The peak response was observed at 2–3 min after addition of 10–4M DA, but [3H]PdBu binding was still increased above basal at 30 min. DA was not acting via an adrenergic receptor. Prazosin (10–6M) blocked the response to NE, suggesting mediation by an α1-adrenergic receptor, but had little effect on the response to DA. Conversely, the D1 receptor antagonist SCH-23390 (10–6M) blocked the response to DA, but only partially inhibited the response to NE. Morphine (10–6M) inhibited the response to DA by 46 ± 14%, but did not affect significantly the response to NE. The DA effect on [3H]PdBu binding is apparently independent of the increase in cyclic AMP seen on D1 receptor activation. Forskolin, apomorphine, and the D1 agonist SKF-38393 all increased cyclic AMP in striatal cells, but were less effective than DA in stimulating [3H]PdBu binding. The D2 agonist quinpirole was ineffective in stimulating either cyclic AMP or [3H]PdBu binding.
Materialart:
Digitale Medien
URL:
http://dx.doi.org/10.1111/j.1471-4159.1992.tb11343.x
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