The identity of the current carriers in canine lingual epithelium in vitro.
The identity of the current carriers in canine lingual epithelium in vitro.
复制标题
体外犬舌上皮中当前携带者的身份。
DOI：
10.1016/0005-2736(85)90496-1
复制
发表时间：
1985
期刊：
影响因子：
--
通讯作者：
DeSimone,JA
中科院分区：
文献类型：
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作者：
Mierson,S;Heck,GL;DeSimone,SK;Biber,TU;DeSimone,JA
舌上皮的离子转运是味觉传导的早期事件。同位素标记的Na+和Cl−的流量在短路条件下测量通过离体犬背舌上皮。上皮细胞积极吸收Na+，并在较小程度上积极分泌Cl−。在对称的Krebs-Henseleit缓冲液条件下，（1）Na+吸收占短路电流（Isc）的46%;（2）存在两条跨细胞Na+通路，一条对阿米洛利敏感，一条对阿米洛利不敏感;（3）哇巴因（ouabain）加入到seretrin溶液中，抑制Isc和主动Na+吸收。当将高渗（0.25 M）NaCl置于粘膜浴中时，I sc和Na+吸收均增加; Na+净吸收至少与I sc一样多。离子替代研究表明，组织可能转运各种较大的离子，尽管不如Na+和Cl−有效。因此，我们已经表明，舌上皮细胞，像其他上皮细胞的胃肠道，积极运输离子。然而，它是不寻常的，无论是在其响应高渗溶液和各种离子，支持跨上皮短路电流。由于高渗条件下的钠离子转运已被证明与味觉神经反应密切相关，因此转运的各种离子可能同样表明转运在味觉转导中具有更广泛的作用。
Ion transport across the lingual epithelium has been implicated as an early event in gustatory transduction. The fluxes of isotopically labelled Na+ and Cl− were measured across isolated canine dorsal lingual epithelium under short-circuit conditions. The epithelium actively absorbs Na+ and to a lesser extent actively secretes Cl−. Under symmetrical conditions with Krebs-Henseleit buffer on both sides,(1) Na+ absorption accounts for 46% of the short-circuit current (I sc);(2) there are two transcellular Na+ pathways, one amiloride-sensitive and one amiloride-insensitive;(3) ouabain, added to the serosal solution, inhibits both I sc and active Na+ absorption. When hyperosmotic (0.25 M) NaCl is placed in the mucosal bath, both I sc and Na+ absorption increase; net Na+ absorption is at least as much as I sc. Ion substitution studies indicate that the tissue may transport a variety of larger ions, though not as effectively as Na+ and Cl−. Thus we have shown that the lingual epithelium, like other epithelia of the gastrointestinal tract, actively transports ions. However, it is unusual both in its response to hyperosmotic solutions and in the variety of ions that support a transepithelial short-circuit current. Since sodium ion transport under hyperosmotic conditions has been shown to correlate well with the gustatory neural response, the variety of ions transported may likewise indicate a wider role for transport in taste transduction.