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No Role for Phospholipase A 2 and Protein Kinase C in the Potentiation by α‐Adrenoceptors of β‐Adrenoceptor‐Mediated Cyclic AMP Formation in Rat Brain
Author(s) -
Robinson Jean P.,
Kendall David A.
Publication year - 1989
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1989.tb07367.x
Subject(s) - long term potentiation , adrenergic receptor , protein kinase a , beta adrenoceptor , phospholipase c , phospholipase d , medicine , chemistry , endocrinology , phospholipase , adrenergic , microbiology and biotechnology , kinase , neuroscience , biology , signal transduction , biochemistry , enzyme , receptor
This study was undertaken to examine the role of phospholipase A 2 and protein kinase C in the potentiation of β‐adrenoceptor‐mediated cyclic AMP formation by α‐ad‐renoceptors in rat cerebral cortical slices. Inhibition of ara‐chidonic acid metabolism by a range of cyclooxygenase and lipoxygenase inhibitors had no effect on the potentiation of isoprenaline‐stimulated cyclic AMP. Conversely, stimulation of leukotriene formation had no effect on the response to isoprenaline. The phospholipase A 2 activator, melittin, stimulated cyclic AMP and potentiated the effect of isoprenaline, but these responses were not influenced by cyclooxygenase or lipoxygenase inhibitors. Indomethacin was also ineffective against the potentiation of vasoactive intestinal peptide‐stimulated cyclic AMP by noradrenaline. Phorbol ester potentiated the cyclic AMP response to isoprenaline, and this potentiation was antagonized by three different putative protein kinase C inhibitors. However, the same inhibitors did not affect the α‐adrenoceptor‐stimulated enhancement of the response to isoprenaline. We have found no evidence, therefore, to support the suggestion that arachidonic acid and its metabolites and/or protein kinase C mediate the α‐adreno‐ceptor modulation of β‐adrenoceptor function.