Matainaho T, Cragoe E J, Manley S W, Huxham G J, Pearson J V, Bourke J R
Department of Physiology and Pharmacology, University of Queensland, St Lucia, Australia.
J Endocrinol. 1989 Oct;123(1):93-7. doi: 10.1677/joe.0.1230093.
Confluent monolayers of cultured porcine thyroid cells transport fluid from the apical to the basal surface, forming circumscribed zones of detachment (domes) from the culture dish substrate. Fluid transport, as measured by increase in dome height, was stimulated by prostaglandin E2 (PGE2; 1 mumol/l) and inhibited by amiloride (0.1-100 mumol/l). Values of the inhibition constant (Ki) with 95% confidence limits for each of a series of amiloride analogues were: 3',4'-dichlorobenzamil (DCB), 0.090 (0.045-0.18) mumol/l; 2',4'-dimethylbenzamil (DMB), 0.14 (0.074-0.27) mumol/l; amiloride, 0.72 (0.33-1.8) mumol/l; 5-(N,N-hexamethylene)amiloride (HMA), 17 (5.9-43) mumol/l; 5-(N-ethyl-N-isopropyl)amiloride (EIPA), 33 (15-71) mumol/l; and 2-guanidinobenzimidazole, 243 (110-570) mumol/l. Triaminopyrimidine was ineffective at concentrations up to 1 mmol/l. Since DCB and DMB are known to have a higher affinity for Na+/H+ channels, while HMA and EIPA show higher affinity for Na+/H+ antiports, it was concluded that PGE2-stimulated fluid transport involved an apical membrane Na+ channel.
培养的猪甲状腺细胞融合单层从顶端向基底表面转运液体，在培养皿基质上形成界限分明的脱离区（穹顶）。通过穹顶高度增加来测量的液体转运，受到前列腺素E2（PGE2；1 μmol/L）的刺激，并被氨氯吡咪（0.1 - 100 μmol/L）抑制。一系列氨氯吡咪类似物的抑制常数（Ki）值及其95%置信限为：3',4'-二氯苯甲酰胺（DCB），0.090（0.045 - 0.18）μmol/L；2',4'-二甲基苯甲酰胺（DMB），0.14（0.074 - 0.27）μmol/L；氨氯吡咪，0.72（0.33 - 1.8）μmol/L；5 -（N，N - 六亚甲基）氨氯吡咪（HMA），17（5.9 - 43）μmol/L；5 -（N - 乙基 - N - 异丙基）氨氯吡咪（EIPA），33（15 - 71）μmol/L；以及2 - 胍基苯并咪唑，243（110 - 570）μmol/L。三氨基嘧啶在浓度高达1 mmol/L时无效。由于已知DCB和DMB对Na+/H+通道具有更高的亲和力，而HMA和EIPA对Na+/H+反向转运体显示出更高的亲和力，因此得出结论，PGE2刺激的液体转运涉及顶端膜Na+通道。
