Expression of a renal Na(+)-nucleoside cotransport system (N2) in Xenopus laevis oocytes

Pflugers Arch. 1994 Jun;427(3-4):381-3. doi: 10.1007/BF00374549.


Xenopus laevis oocytes have been used for the expression of a renal, pyrimidine-selective, Na(+)-nucleoside cotransporter (N2). As compared to its uptake in water-injected oocytes, Na(+)-dependent thymidine uptake was enhanced in a time- and dose-dependent manner in oocytes injected with rat renal cortex total poly(A)+ RNA. An increased uptake was also observed after injection of size fractionated rat renal cortex poly(A)+ RNA (2-3 kb). Consistent with the selectivity of the N2 nucleoside transporter, cytidine significantly inhibited Na(+)-dependent thymidine uptake in oocytes injected with total poly(A)+ RNA whereas guanosine and formycin B did not. Na(+)-dependent thymidine uptake was also enhanced in oocytes injected with size fractionated human renal cortex poly(A)+ RNA (2-3 kb). The above data demonstrate functional expression of renal cortex, Na(+)-nucleoside cotransporters in Xenopus laevis oocytes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Animals
  • Carrier Proteins / biosynthesis*
  • Carrier Proteins / genetics
  • Carrier Proteins / physiology
  • Humans
  • In Vitro Techniques
  • Ion Transport
  • Kidney Cortex / metabolism
  • Oocytes / metabolism*
  • Poly A
  • RNA
  • RNA, Messenger
  • Sodium / metabolism*
  • Symporters*
  • Thymidine / metabolism
  • Xenopus laevis


  • Carrier Proteins
  • RNA, Messenger
  • Symporters
  • sodium-nucleoside cotransporter
  • Poly A
  • RNA
  • Sodium
  • Thymidine