Functional expression of basolateral Cl−/HCO3− exchange from rat jejunum in Xenopus laevis oocytes

✍ Scribed by Marisa Tosco; Maria novella Orsenigo; Giulia Gastaldi; Alide Faelli

• Publisher: John Wiley and Sons
• Year: 1998
• Tongue: English
• Weight: 169 KB
• Volume: 16
• Category: Article
• ISSN: 0263-6484
• DOI: 10.1002/(sici)1099-0844(199803)16:1<35::aid-cbf759>3.0.co;2-e

✦ Synopsis

PolyA RNA isolated from rat jejunum was injected into Xenopus laevis oocytes and expression of Cl À aHCO À 3 antiport was investigated by means of 36 Cl À uptake. Two days after injection of 50 ng of polyA RNA, Cl À uptake was signi®cantly increased with respect to water-injected oocytes. The expressed transport was inhibited by 0 . 2 mM DIDS, whereas endogenous Cl À uptake was unaected by this disulphonic stilbene. After sucrose density gradient fractionation, the highest expression of DIDS-sensitive Cl À uptake was detected with mRNA size fraction of about 2±4 kb in length. The expressed Cl À uptake can occur against a Cl À concentration gradient and is unaected by the known Cl À channel blocker anthracene-9-carboxylic acid. Cl À transport mechanism has properties similar to jejunal basolateral Cl À aHCO À 3 exchange with regard to Na dependence.