Human proximal duodenal alkaline secretion is mediated by Cl-/HCO3- exchange and HCO3- conductance.
Human proximal duodenal alkaline secretion is mediated by Cl-/HCO3- exchange and HCO3- conductance.
复制标题
人近端十二指肠碱性分泌是由 Cl-/HCO3- 交换和 HCO3- 电导介导的。
DOI：
10.1023/a:1018895405362
复制
发表时间：
1998
影响因子：
3.1
通讯作者：
Isenberg,JI
中科院分区：
文献类型：
--
作者：
Nyberg,L;Pratha,V;Hogan,DL;Rapier,RC;Koss,MA;Isenberg,JI
近端十二指肠上皮分泌碳酸氢盐进入粘附的粘液层，从而保护粘膜免受胃酸和胃蛋白酶的损伤。虽然碳酸氢盐的分泌被许多激动剂和拮抗剂所刺激和抑制，但顶端阴离子转运途径尚未完全解决。目的是评估顶端Cl-/HCO 3-交换和Cl-：HCO 3-传导是否参与十二指肠粘膜碳酸氢盐分泌（DMBS）。在健康志愿者中，分离十二指肠近端4cm，用生理盐水或4，4′-二异硫氰基-2，2 ′-二磺酸（DIDS）灌流，用PGE 2或磷酸二酯酶激动剂或茶碱刺激碳酸氢盐分泌和跨上皮电位差（PD），以增加cAMP。管腔DIDS可消除PGE 2刺激的DMBS，但对PD的增加没有影响，也不能显著改变茶碱诱导的DMBS和PD。因此，在人近端十二指肠，PGE 2和cAMP激活不同的HCO转运途径2，可能涉及DIDS敏感的Cl-/HCO 3-交换和DIDS不敏感的HCO 3-传导。
The proximal duodenal epithelium secretesbicarbonate into an adherent mucus layer, therebyprotecting the mucosa from injury by gastric acid andpepsin. While bicarbonate secretion is stimulated andinhibited by a number of agonists and antagonists, theapical anion transport pathways have not been addressedfully. The objective was to assess if apicalCl-/HCO3-exchange andCl-:HCO3-conductanceare involved in duodenal mucosal bicarbonate secretion(DMBS). In healthy volunteers, the proximal 4 cm ofduodenum was isolated, perfused with either saline or4,4′-diisothiocyano-2,2′-disulfonic acid(DIDS), and bicarbonate secretion and transepithelial potentialdifference (PD) were stimulated by eitherPGE2or the phosphodiesterase inhibitortheophylline to increase cyclic AMP. Luminal DIDSabolished PGE2-stimulated DMBS, yet had no effect on the increase in PD andfailed to significantly alter theophylline-induced DMBSand PD. Therefore, in human proximal duodenum, itappears that PGE2and cAMP activate distinctHCO transport pathways 2 likely involving a DIDS-sensitiveCl-/HCO3-exchanger andDIDS-insensitive HCO3-conductance.