D2 but not D1 dopamine receptor stimulation augments brain signaling involving arachidonic acid in unanesthetized rats

来自 EBSCO

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作者：

AK Bhattacharjee，L Chang，HJ Lee，RP Bazinet，R Seemann，SI Rapoport

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摘要：

Rationale and objectives Signal transduction involving the activation of phospholipase A 2 (PLA 2 ) to release arachidonic acid (AA) from membrane phospholipids, when coupled to dopamine D 1 - and D 2 -type receptors, can be imaged in rats having a chronic unilateral lesion of the substantia nigra. It is not known, however, if the signaling responses occur in the absence of a lesion. To determine this, we used our in vivo fatty acid method to measure signaling in response to D 1 and D 2 receptor agonists given acutely to unanesthetized rats. Methods [1- 14 C]AA was injected intravenously in unanesthetized rats, and incorporation coefficients k * for AA (brain radioactivity/integrated plasma radioactivity) were measured using quantitative autoradiography in 61 brain regions. The animals were administered i.v. the D 2 receptor agonist, quinpirole (1mg kg 1 , i.v.), the D 1 receptor agonist SKF-38393 (5mg kg 1 , i.v.), or vehicle/saline. Results Quinpirole increased k * significantly in multiple brain regions rich in D 2 -type receptors, whereas SKF-38393 did not change k * significantly in any of the 61 regions examined. Conclusions In the intact rat brain, D 2 but not D 1 receptors are coupled to the activation of PLA 2 and the release of AA.

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关键词：

Dopamine Phospholipase A2 SKF-38393 Quinpirole Arachidonic acid Brain

DOI：

10.1007/s00213-005-2208-4

被引量：

142

年份：

2005