Ligands of purinergic receptors stimulate electrogenic H+‐transport of neutrophils

[摘要]

The possible role of ATP, acting as a ligand on cell surface receptor was investigated in the activation of the electrogenic H⁺-transporting pathway of porcine neutrophil granulocytes. (1) ATP brought about 2.1-fold increase in the rate of H⁺-efflux. (2) The order of potency of different nucleotides suggests, that ATP acts on P₂ type purinoceptor. (3) The effect of the nucleotides was prevented by inhibition of phospholipase A₂. (4) Inhibition of the metabolism of arachidonic acid (AA) via the cyclooxygenase pathway had no effect, whereas inhibition of the lipoxygenase pathway significantly enhanced H⁺-release. This is the first report about activation of the H⁺-transporter by physiological stimulator acting on the cell surface.

[学科分类] 生物化学/生物物理

[关键词] Electrogenic H+-transporter;Adenosine triphosphate;Arachidonic acid;Phopholipase A2;Neutrophil granulocyte;AA;arachidonic acid;ATPγS;adenosine5′-O-3-thiotriphosphate;BCECF/AM;2′;7′-bis(carboxyethyl)-5(6)-carboxyfluorescein acetoxymethyl ester;BPB;p-bromophenacyl bromide;CTP;cytidine 5′-triphosphate;DIDS;4′;4′-diisothiocyanostilbene-2;2′-disulfonate;fMLP;formyl-methionyl-leucine-phenylalanine;IBP;iodonium biphenyl;K 0.5;half-maximal activating concentration;NDGA;nordihydro-guaiaretic acid;pHi;intracellular pH;pHo;extracellular pH;PKC;protein kinase C;PLA2;phospholipase A2;PMA;phorbol 12-myristate 13-acetate;PMN;polymorphonuclear leukocytes;UTP;uridine 5′-triphosphate