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Brush Border Vesicle Transport Effects of 1,25-Dihydroxy Vitamin D3

  • Jules B. Puschett
  • J. Egel
  • J. Pfanstiel
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 178)

Abstract

Evidence has accumulated from investigations performed in this laboratory and in others that the renal tubular effect of 1,25-dihydroxy vitamin D3 (1,25 D3), the active form of the vitamin, is to increase phosphate reabsorption by the kidney (1–3). We recently reported that the infusion of 2.5 ng of 1,25 D3 per hour along with 0.2 U of PTH/hr. for six hours resulted in an antiphosphaturia in thyroparathyroidectomized (TPTX), vitamin D-deficient (−D) rats (3). This dose of the metabolite has been considered to be in the physiological range, and was not effective unless given with the non-phosphaturic “permissive” dose of PTH. The development of the brush border vesicle (BBV) transport technique (4) provided us with an opportunity to study the locus of this antiphosphaturic action of the metabolite. Furthermore, glucose metabolism has been reported to be linked to phosphate (Pi) transport events; Rasmussen and his coworkers have reported (5) that parathyroid hormone (PTH), a substance which diminishes phosphate uptake by brush border vesicles (4), increases gluconeogenesis (GNG). Accordingly, we examined the effect of the antiphosphaturic agent 1,25 D3, on BBV Pi uptake and on GNG.

Keywords

Parathyroid Hormone Phosphate Transport Brush Border Membrane Vesicle Transport Technique Dihydroxy Vitamin 
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References

  1. 1.
    Puschett JB, Kuhrman MS: Renal tubular effects of 1,25-dihydroxy vitamin D3: Interactions with vasopressin and parathyroid hormone in the vitamin D-depleted rat. J Lab Clin Med 92: 895, 1978.PubMedGoogle Scholar
  2. 2.
    Popovtzer MM, Robinette JB, DeLuca HF and Holick MF: The acute effect of 25-hydroxycholecalciferol on renal handling of phosphorus. J Clin Invest 53: 913, 1974.PubMedCrossRefGoogle Scholar
  3. 3.
    Puschett JB, Georgaki H: Acute effect of a “physiological” dose of 1,25-dihydroxy vitamin D3 on renal phosphate transport. Endocr Res Comm 9: 135, 1982.CrossRefGoogle Scholar
  4. 4.
    Puschett JB, Kempson SA and Kowalski JC: Inhibition of renal brush border phosphate transport and stimulation of renal gluconeogenesis by cyclic AMP and parathyroid hormone. (In press).Google Scholar
  5. 5.
    Rasmussen H, Nagata N: Renal gluconeogenesis: Effects of parathyroid hormone and dibutyryl 3’,5’-AMP. Biochim Biophys Acta 215: 17, 1970.PubMedCrossRefGoogle Scholar

Copyright information

© Plenum Press, New York 1984

Authors and Affiliations

  • Jules B. Puschett
    • 1
  • J. Egel
    • 1
  • J. Pfanstiel
    • 1
  1. 1.Renal-Electrolyte Division Department of MedicineUniversity of PittsburghPittsburghUSA

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