Greenberg S S, Johns A, Kleha J, Xie J, Wang Y, Bianchi J, Conley K
Louisiana State University, Department of Medicine, New Orleans.
J Pharmacol Exp Ther. 1994 Mar;268(3):1352-61.
Phenol red (PR) is used as a pH indicator in cell culture medium. We found that cell culture medium containing PR relaxed canine lingual arteries (LA) contracted by the thromboxane A2/prostaglandin endoperoxide (TPE) receptor agonist (15S)-hydroxy-11-alpha-9-alpha- (epoxymethano)prosta-5Z,13E-dienoic acid (U46619). We tested the effect of PR and the TPE receptor antagonist ONO-3708 on U46619, prostaglandin F2 alpha (PGF2 alpha), phenylephrine (PE) and potassium chloride (KCl)-induced contraction of the LA and on human platelet aggregation to U46619, ADP, arachidonic acid (AA), A23187 and thrombin. U46619, PGF2 alpha, KCl and PE produced equal tension development of the LA. PR relaxed the LA contracted with U46619 and PGF2 alpha with IC50 concentrations of 18.3 +/- 10 and 37.3 +/- 8.8 microM, respectively. ONO-3708 inhibited the contractions to U46619 and PGF2 alpha with IC50 of 9.4 +/- 2.2 and 12.2 +/- 2.2 nM, respectively. However, PR (300 microM) and ONO-3708 (300 nM) did not affect contraction of the LA to KCl or PE. PR inhibited human platelet aggregation, in vitro, to AA and U46619 and second wave aggregation to ADP but did not affect thrombin or first wave ADP-mediated platelet aggregation. PR inhibited U46619 and AA-induced changes in cyclic AMP and Fura-2 calcium transients in platelets and LA. However, PR did not affect the activation of cyclic AMP or intracellular calcium ion in platelets or calcium influx and the release of intracellular calcium ion in canine LA produced by ryanodine, KCl and PE. The concentration of PR in many culture media is between 40 and 70 microM. The data support the conclusion that PR, in concentrations used as a pH indicator, is a selective antagonist of TPE receptors.
酚红（PR）在细胞培养基中用作pH指示剂。我们发现，含有PR的细胞培养基可舒张由血栓素A2/前列腺素内过氧化物（TPE）受体激动剂（15S）-羟基-11-α-9-α-（环氧亚甲基）前列腺-5Z，13E-二烯酸（U46619）引起收缩的犬舌动脉（LA）。我们测试了PR和TPE受体拮抗剂ONO-3708对U46619、前列腺素F2α（PGF2α）、去氧肾上腺素（PE）和氯化钾（KCl）诱导的LA收缩的影响，以及对人血小板对U46619、ADP、花生四烯酸（AA）、A23187和凝血酶聚集的影响。U46619、PGF2α、KCl和PE使LA产生同等程度的张力变化。PR可舒张由U46619和PGF2α引起收缩的LA，其IC50浓度分别为18.3±10和37.3±8.8μM。ONO-3708抑制对U46619和PGF2α的收缩，其IC50分别为9.4±2.2和12.2±2.2 nM。然而，PR（300μM）和ONO-3708（300 nM）不影响LA对KCl或PE的收缩。PR在体外抑制人血小板对AA和U46619的聚集以及对ADP的第二波聚集，但不影响凝血酶或第一波ADP介导的血小板聚集。PR抑制血小板和LA中U46619和AA诱导的环磷酸腺苷（cAMP）和Fura-2钙瞬变的变化。然而，PR不影响血小板中环磷酸腺苷的激活或细胞内钙离子，也不影响犬LA中由ryanodine、KCl和PE引起的钙离子内流和细胞内钙离子释放。许多培养基中PR的浓度在40至70μM之间。这些数据支持以下结论：用作pH指示剂的浓度下，PR是TPE受体的选择性拮抗剂。
