ATP a potent regulator of inositol phospholipids-phospholipase C and lipid mediators in brain cortex
Selected contents from this journal
Languages of publication
Adenosine-5'triphosphate (ATP) is stored and co-released with various neurotransmitters but it may also act as a fast excitatory neurotransmitter trough the activation of purinoreceptor(s).In this study the effcet of ATP on phospholipase C (PLC) degrading labelled PtdIns(4,5)P2 and PtdIns in brain cortex slices, brain homogente and subcellular fractions was investigated.It was found the ATP added into brain slices activated significantly and specifically PtdIns(4,5)P2 degradation and this process was inhibited by theophylline.Moreover, ATP maintained a higher level of inositol(1,4,5,)P3 radioactivity in total water-soluble inositol metabolites.However, ATP added directly for the assay of PLC into brain homogenate of subcellular fractions inhibits phosphoinositide degradation in a eceptor-independend manner and suppresses conversion of Ins(1,4,5)P3 into Ins(1,4)P2.Our results indicate that ATP acting extracellularly through a purinergic receptor(s) activates PtdIns(4,5)P2 degradation and release of Ins(1,4,5)P3.ATP acting directly on PLC inhibits in a receptor-independent manner phosphoinositide degradation, and protect against liberation of lipid-derived second messengers.
Publication order reference