These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: The renal cortical Na-HCO3 cotransporter: V. expression in Xenopus oocytes.
    Author: Ruiz OS, Qiu YY, Arruda JA.
    Journal: Proc Soc Exp Biol Med; 1996 Feb; 211(2):199-204. PubMed ID: 8599028.
    Abstract:
    The Na-HCO3 cotransporter is the main system responsible for HCO3 transport from proximal tubule cells into the blood. the expression of the renal cortical basolateral Na-HCO3 cotransporter was studied in Xenopus laevis oocytes. Injection of mRNA prepared from renal cortex into oocytes enhanced HCO3-dependent 22Na uptake on average 6-fold, (range:2-44) compared with vehicle-injected oocytes, without altering 22Na uptake in presence of gluconate. These findings indicate that mRNA selectively expresses Na-HCO3 cotransporter activity without altering diffusive 22Na uptake. The expressed Na-HCO3 cotransporter activity had a Km for Na of 20 mM, was electrogenic and sensitive to disulfonic stilbenes. In presence of HCO3, the expressed Na-HCO3 cotransporter activity was like the native cotransporter, enhanced by carbonate or sulfite, a finding compatible with the existence of distinct sites for HCO3 and carbonate on the transport system. After fractionation by a sucrose density gradient, the mRNA fraction responsible for the Na-HCO3 cotransporter was found to be between 1.50 and 3.48 kb classes.
    [Abstract] [Full Text] [Related] [New Search]