Inhibitory effect of dopamine on Ca(2+)-calmodulin-dependent protein kinase II activity in rat hippocampal slices.
Abstract
AIM:
To study the effect of dopamine (DA) on Ca(2+)-calmodulin dependent protein kinase II (CCDPK II) activity in rat hippocampus.
METHODS:
Using rat hippocampal slices as an in vitro model, the activity of CCDPK II was examined by the method of 32P-incorporation.
RESULTS:
Exogenous DA reduced CCDPK II activity in hippocampal slices in a concentration- and time-dependent manner. Removal of extracellular calcium antagonized the DA-induced inhibition of CCDPK II activity, partially or completely. The activity of CCDPK II was markedly decreased by apomorphine (a nonselective DA receptor agonist), SKF38393 (a selective D1-like DA receptor agonist), or quinpirole (a selective D2-like DA receptor agonist). The inhibition of CCDPK II activity induced by exogenous DA was abolished by preincubation with Sch-23390, a selective D1-like DA receptor antagonist, or domperidone, a selective D2-like DA receptor antagonist.
CONCLUSION:
DA has an inhibitory effect on CCDPK II activity in rat hippocampus, related to stimulation of D1-like and D2-like receptors and calcium influx.
Keywords:
To study the effect of dopamine (DA) on Ca(2+)-calmodulin dependent protein kinase II (CCDPK II) activity in rat hippocampus.
METHODS:
Using rat hippocampal slices as an in vitro model, the activity of CCDPK II was examined by the method of 32P-incorporation.
RESULTS:
Exogenous DA reduced CCDPK II activity in hippocampal slices in a concentration- and time-dependent manner. Removal of extracellular calcium antagonized the DA-induced inhibition of CCDPK II activity, partially or completely. The activity of CCDPK II was markedly decreased by apomorphine (a nonselective DA receptor agonist), SKF38393 (a selective D1-like DA receptor agonist), or quinpirole (a selective D2-like DA receptor agonist). The inhibition of CCDPK II activity induced by exogenous DA was abolished by preincubation with Sch-23390, a selective D1-like DA receptor antagonist, or domperidone, a selective D2-like DA receptor antagonist.
CONCLUSION:
DA has an inhibitory effect on CCDPK II activity in rat hippocampus, related to stimulation of D1-like and D2-like receptors and calcium influx.