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: Nephron heterogeneity of phosphate reabsorption: effect of parathyroid hormone.
    Author: Haramati A, Haas JA, Knox FG.
    Journal: Am J Physiol; 1984 Feb; 246(2 Pt 2):F155-8. PubMed ID: 6696117.
    Abstract:
    We evaluated the response of superficial and deep nephron proximal tubules to PTH in thyroparathyroidectomized (TPTX) rats fed a normal phosphate diet (0.7%). As phosphate reabsorption is not detectable in the ascending limb of the loop of Henle, fractional phosphate delivery (FDPi%) to the superficial early distal tubule and papillary loop of Henle reflects delivery from superficial and deep nephron proximal tubules, respectively. Re-collection micropuncture experiments were performed in nine acutely TPTX rats before and after the infusion of PTH (33 U/kg bolus; 1 U X kg-1 X min-1). In response to PTH, fractional phosphate excretion increased from 3.3 to 26.2% (P less than 0.05). FDPi% was less from the deep than from the superficial proximal tubule (5.7 vs. 15.7%, P less than 0.05) prior to PTH, indicating enhanced phosphate reabsorption by deep compared with superficial proximal tubules. During PTH infusion, FDPi% was increased in both nephron groups compared with control (P less than 0.05), but there were no differences in phosphate delivery between deep (28.0%) and superficial (29.7%) proximal tubules. We conclude that in acutely volume-expanded TPTX rats, infusion of a pharmacologic dose of PTH decreases phosphate reabsorption in both superficial and deep nephrons. Furthermore, the heterogeneity of FDPi% from deep compared with superficial proximal tubules seen in TPTX rats is absent during PTH infusion.
    [Abstract] [Full Text] [Related] [New Search]