Dual regulation of arachidonic acid release by P2U purinergic receptors in dibutyryl cyclic AMP-differentiated HL60 cells.

摘要: ATP promoted biphasic effects on both basal and fMLP-stimulated arachidonic acid (AA) release in neutrophil-like HL60 cells: stimulation the micromolar range (EC50 = 3.2 +/- 0.9 microM) inhibition at higher concentrations 90 11 microM). also inhibited UTP- platelet activating factor-stimulated AA release. Only stimulatory of or phospholipase C were observed. The inhibitory effect was not due to reacylation released AA, chelation extracellular Ca2+, cell permeabilization, changes rise [Ca2+]i induced by agonist. rapid, being detected within 5-15 s. could be desensitized pretreatment cells with 2 mM ATP, but 20 microM concentration that resulted maximal inositol phosphates. neither dependent generation adenosine hydrolysis nor result direct interaction P1 purinergic receptors. Among other nucleotides tested (CTP, GTP, ITP, TTP, XTP, 5'-(beta,gamma-methylene)triphosphate (AMP-PCP), adenyl-5'-yl imidodiphosphate (AMP-P(NH)P), ADP, 5'-O-(3-thiotriphosphate) (ATP gamma S), UTP), only UTP S displayed potencies efficacies almost identical those ATP. exhibited 60-300 results are consistent a model dual regulation two distinct subtypes P2U receptors cells.