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: Effect of experimentally induced hypothyroidism on sulfate renal transport in rats.
    Author: Sagawa K, Murer H, Morris ME.
    Journal: Am J Physiol; 1999 Jan; 276(1):F164-71. PubMed ID: 9887092.
    Abstract:
    Decreased serum sulfate concentrations are observed in hypothyroid patients. However, the mechanism involved in thyroid hormone-induced alterations of renal sulfate homeostasis is unknown. The objectives of this investigation were to determine the effect of 6-propyl-2-thiouracil (PTU)-induced hypothyroidism in rats on 1) the in vivo serum concentrations, renal clearance, and renal reabsorption of sulfate, 2) the in vitro renal transport in brush-border membrane (BBM) and basolateral membrane (BLM) vesicles, and 3) the cellular mechanism of the hypothyroid-induced alteration in sulfate renal transport. Serum sulfate concentrations, renal fractional reabsorption of sulfate, and creatinine clearance were decreased significantly in the hypothyroid group. The Vmax values for sodium-sulfate cotransport in BBM were significantly decreased in the kidney cortex from the hypothyroid animals (0.90 +/- 0.31 vs. 0.49 +/- 0.08 nmol. mg-1. 10 s-1, n = 5-6, P < 0.05) without changes in Km. There were no significant differences in Vmax and Km for sulfate/anion exchange transport in BLM. Sodium-dependent sulfate transporter (NaSi-1) mRNA and protein levels were significantly lower in the kidney cortex from hypothyroid rats. Hypothyroidism did not alter the membrane motional order (fluidity) in BBM and BLM, which indicates that the changes in the membrane fluidity do not represent the mechanism for the altered renal transport. These results demonstrate that PTU-induced hypothyroidism decreases sodium-sulfate cotransport by downregulation of the NaSi-1 gene.
    [Abstract] [Full Text] [Related] [New Search]