Discuss the effects of FGF23 and PTH on phosphate and calcitriol.

52 Comments

  • Muhammad Soobadar


    There is increased FGF23 in early CKD . FGF 23 works by increase phosphate excretion in kidney by working on renal tubules by binding klotho co-receptor and activating its FGFR-1 and FGFR-3 and leads to decrease in concentration of sodium co transporters NAPI2a NAPI2c through Protein Kinase and A /C dependent pathways. It also inhibits 1 alpha hydroxylase decreasing 1 25 hidroxyvitamin d and decreasing intestinal phosphate absorption. PTH is phosphaturic too by binding its own receptor and then leading as FGF23 to decrease in concentration of sodium co-tranporters NAPI2a and NAPI2C through protein kinase A/C dependent pathways.

    FGF23 and PTH interestingly have different effect on 1a -hydroxlyase. fgf 23 decrease 1a hydroxylase and decrease 1 25 OH therefore decreased calcium absorption from gut.
    PTH increases 1 a hydroxlase and low a hydroxlase stimulate PTH too. there increasing calcium via intestinal absorption. PTH acts on bones by stimulating osteoblast which increase expression of RANKL allowing for differentiation into osteoblast and osteocyte. it leads bone resorption and release of calcium into blood from bone.

  • HASSAN ALYAMMAHI


    Phosphate tends to accumulate in the very early stages of CKD
    FGF23 increases first followed by PTH, both of them are phosphaturic.
    This phosphaturic effect is achieved by decreasing NaPi2 transporter
    PTH increases 1a-Hydroxylase thereby tending to increase active vitamin D and consequently tending to restore serum calcium.
    FGF23 has the opposite effect on 1a-Hydroxylase (inhibition), and hence tending to lower serum calcium

  • Marwa Alm


    * FGF23 inhibit 1alpha hydroxylase hence vitamin D activation decreasing intestinal absorption of phosphorus (on the other hand vitamin D inhibit FGF23)
    * FGF23 inhibit NaPi2a,c in PCT, decreasing phosph reabsorption, promoting its excretion (phosphaturic effect)
    * FGF23 inhibit NaPi2b decreasing intestinal absorption of phosphorus

    * PTH stimulate 1alpha hydroxylase, promoting calcitriol activation
    * PTH decreases phosphorus reabsorption (phosphaturic hormone)

  • Mohamed Abdulahi Hassan


    The effects of FGF23 and PTH on phosphate and calcitorial.
    The increase of PTH and FGF23 decrease in serum calcitorial in later stages of CKD.
    FGF23 and PTH have collaborating effects on renal phosphate excretion and they have opposite effects on calcitorial synthesis , FGF23 inhibits the alpha 1 hydroxylase decreasing the synthesis of calcitorial and PTH stimulates the production of alpha 1 hydroxylase and increases the calcitorial synthesis and both increase phosphate excretion by decreasing the concentration of Napi2

  • Radwa Ellisy


    (PHOSPHORUS)
    Both FGF 23 and PTH have a phosphaturic effect via action on tubular Napi2a and NaPi2c cotransporters in the renal tubules.
    (Calcitriol)
    FGF 23 decreases alpha-hydroxylase activity by binding to Klotho co-receptors on FGFR-1 and 3
    while PTH increases 1 alpha-hydroxylase activity increasing calcitriol level synthesis

  • Asmaa Salih KHUDHUR


    Despite the fact that FGF23 and PTH have synergistic effects in relation to the renal excretion of phosphate, they have opposite effects on calcitriol synthesis. FGF23 inhibits 1-α-hydroxylase by decreasing the synthesis of calcitriol, whereas PTH stimulates the production of 1-α-hydroxylase, increasing calcitriol synthesis .FGF23 exerts its tubular effect by binding to its Klotho co-receptor and activating its FGFR-1 FGFR-3 receptors, while PTH does so by binding to its specific receptor. Both increase the phosphate excretion by reducing the concentration of the sodium cotransporters NaPi2a and NaPi2c, through Protein Kinase A and C -dependent pathways.

  • Mahmud ISLAM


    Both FGF-23 and PTH are a phosphaturic effect. They have an opposite effect on alpha-hydroxylase. PTH increases the effect trying to incase the calcitriol synthesis while FGF-23 shows an inhibitory effect

    • Eman Nagy


      Thanks Dr. Mahmud.
      In addition:

      ·       FGF23 inhibits 1-α-hydroxylase by decreasing the synthesis of calcitriol.

      ·       PTH stimulates the production of 1-α-hydroxylase, increasing calcitriol synthesis.

      ·       FGF23 exerts its tubular effect by binding to its Klotho co-receptor and activating its FGFR-1 FGFR-3 receptors. While PTH does so by binding to its specific receptor.

  • Rabab ALaa Eldin keshk Rabab


    The effect of fgf23 on po4 is a phosphaturic effect via increase its excretion and prevent reabsorption in proximal tubules and after the progression of ckd decrease koltho and more increase in fgf23 with decrease po4 excretion due to damage kideny tissue with decrease level of calciterol
    The effect of pth early in disease have senirgistic effect with fgf23 in it’s phosphaturic effect and increase level of alpha hydroxylase to increase level of calciterol

    • Eman Nagy


      Great Dr. Rabab.
      I want to add some points:
      Both FGF23 and PTH have opposite effects on calcitriol synthesis

      ·       FGF23 inhibits 1-α-hydroxylase by decreasing the synthesis of calcitriol.

      ·       PTH stimulates the production of 1-α-hydroxylase, increasing calcitriol synthesis.

  • Rola Kotob


    Up to (GFR) of around 30–40 ml/min, serum calcium and phosphate values usually remain within the normal range, changes usually manifested with GFR below 20–30 ml/min.
     In contrast, calcitriol begins to decrease early in the course of CKD (GFR between 70 and 80 ml/min), calcidiol and PTH increase abit later, from GFR of 60–70 ml/min

    FGF23 inhebits 1-alfa hydroxylase in the kidney decreasing calcitriol while PTH increases 1-alfa hydroxylase in the kidney
    FGF23 and PTH in early CKD both increase serum phosphate excretion then with progression of Ckd and nephron loss and decrease klotho expression serum phosphate starts to increase and serum calcitriol decrease.
     

  • Elsayed Ghorab


    FGF -23 role on phosphate and calcitriol
    has role in inhibition of na/ pi cotransporter in the proximal tubule so decrease reabsorption of phosphate and stimulation of renal po4 excretion required klotho for its action as phosphaturic action
    –suppression of intestinal phosphate absorption
    BUT its effect on calcitriol
    –inhibit of renal 1-alfa hydroxylase
    PTH hormone synergistic effect for urinary phosphate excretion
    and increase production of 1-alfa hydroxylase and increase level of calcitriol

  • Emad mohamed mokbel Salem


    EFFECT OF FGF23 ON PTH AND PHOSPHATE AND CALCITRIOL
    ===================
    FGF23 AND PTH HAVE SYNERGISTIC EFFECTS IN RELATION TO THE RENAL EXECRETION OF PHOSPHATE BUT HAVE OPPOSITE EFFECT ON CALCITRIOL
    1-EFFECT OF FGF23 ON PHOSPHATE
    act as phosphaturic hormone >increase phosphate execrtion by inhibition of Na/pi cotransporter at PCT
    ==========
    2-EFFECT OF FGF23 ON CALCITRIOL
    reduce calcitriol by inhibition of 1 alfa hydroxylation
    =================
    PTH increase calcitiriol by activation of 1 alfa hydroxylation from kidney

  • Ahmed Altalawy


    FGF23 and PTH have stimulatory effects on phosphate excretion in the kidney. They have opposing effects on the production of calcitriol. 
    FGF23 inhibits 1–hydroxylase through lowering calcitriol production.
    PTH increases calcitriol synthesis by stimulating the formation of 1–hydroxylase.

  • Amna Kununa


    During the early stage of CKD, “normal” phosphorus levels are maintained by continual increases in FGF-23 and PTH levels.

    Eventually, this compensatory mechanism is overwhelmed with a further decline in kidney function.

    FGF23 and PTH are both phosphaturic hormones, reducing renal phosphate reabsorption downregulation of the luminal membrane NaPi2a and NaPi2c through protein kinase A and C- dependent pathways.

    Feedback loops for both PTH and FGF-23 are dependent on calcitriol:

    • PTH increases 1-alpha-hydroxylase and, therefore, the production of calcitriol, which in turn inhibits further PTH release.
    • Whereas, FGF-23 inhibits 1-alpha-hydroxylase and decreases calcitriol production, which will inhibit FGF-23 secretion.
  • Mahmoud Elsheikh


    FGF23 and PTH both are phosphaturic by affecting sodium cotransporters NaPi2a and NaPi2c, in proximal tubule.

    FGF23 inhibit 1 alpha hydroxylase leading to calcitriol synthesis
    PTH stimulates calcitriol production

  • Ibrahim Omar


    effects of FGF23 and PTH on phosphate :

    • both are phosphaturic agents trying to maintain phosphate balance in CKD.

    effects of FGF23 and PTH on calcitriol :

    • PTH stimulate the activation of Vit. D by increasing the activity of alpha-1 hydroxylase therefore increasing calcitriol.
    • FGF-23 inhibits the activation of Vit. D by decreasing the activity of alpha-1 hydroxylase therefore decreasing calcitriol.
  • Rania Mahmoud


    Discuss the effects of FGF23 and PTH on phosphate?
    FGF23 and PTH have stimulatory effects on phosphate excretion in the kidney. They have opposing effects on the production of calcitriol. 

    Discuss the effects of FGF23 and PTH on calcitriol?
    FGF23 inhibits 1–hydroxylase through lowering calcitriol production.
    PTH increases calcitriol synthesis by stimulating the formation of 1–hydroxylase.

  • Rihab Elidrisi


    One of the crucial points in CKD-MBD, despite the synergistic effect of FGF23 and PTH in decreasing the phosphate level through the kidney, they have opposite effects on calcitriol synthesis, FGF23 inhibits1alpha hydroxylation, while PTH increases it.

  • Ashraf Ahmed Mahmoud


    Discuss the effects of FGF23 and PTH on phosphate?

    FGF23 and PTH both are phosphaturic ( increase po4 excretion ) by reducing the concentration of the sodium cotransporters NaPi2a and NaPi2c, in proximal tubule.

    Discuss the effects of FGF23 and PTH on calcitriol?

    • FGF23 inhibit 1 alpha hydroxylase leading to calcitriol synthesis
    • PTH enhance calcitriol production
  • Mark Nagy Zaki Amin Mark


    As regard phosphate they are the same. both of them increase po4 excretion from the kidney but this is different in calcitriol. PTH stimulate calcitriol action but FGF-23 inhibit calcitriol action in contrary .

  • Ben Lomatayo


    -Discuss the effects of FGF23 and PTH on phosphate?

    • FGF23 / PTH both are phosphaturic; they reduce the concentration of NaPi 2a/NaPi 2c in the PCT through protein kinase A & C dependent pathways
    • FGF23 work in the PCT through renal Klotho, FGFR-1, FGFR-3
    • PTH worsk through binding to its specific receptor

    -Discuss the effects of FGF23 and PTH on calcitriol?

    • FGF23/PTH both have opposite effect on calcitriol
    • FGF23 inhibit calcitriol synthesis
    • PTH enhance calcitriol production

  • Alaa Abdel Nasser


    Despite the fact that FGF23 and PTH have synergistic effects in relation to the renal excretion of phosphate, they have opposite effects on calcitriol synthesis.

    FGF23 inhibits 1-α-hydroxylase by decreasing the synthesis of calcitriol, whereas PTH stimulates the production of 1-α-hydroxylase, increasing calcitriol synthesis.

    FGF23 exerts its tubular e ect by binding to its Klotho co-receptor and activating its FGFR-1 FGFR-3 receptors, while PTH does so by binding to its specific receptor.

    Both increase the phosphate excretion by reducing the concentration of the sodium cotransporters NaPi2a and NaPi2c, through Protein Kinase A and C -dependent pathways 

  • MOHAMMED HAJI HASSAN


     Effects of FGF23 and PTH on phosphate and calcitriol
    Synergistic effect of FGF23 and PTH:
    FGF23 binds to its Klotho co-receptor and activates FGFR-1 FGFR-3 receptors while PTH does so by binding to its specific receptor Both of them increase the phosphate excretion by reducing the concentration of the sodium cotransporters NaPi2a and NaPi2c, through Protein Kinase A and C dependent pathways.

    The opposite effect of FGF23 and PTH:
    FGF23 inhibits 1-α-hydroxylase by decreasing the synthesis of calcitriol, while PTH stimulates the production of 1-α-hydroxylase, increasing calcitriol synthesis.
     

  • Nour Al Natout


    FGF23 and PTH are both phosphaturic hormone.
    FGF23 act with it cofactor klotho on renal tubules (fgf receptor 1and3).
    PTH act on it receptors on kidney.
    Both receptor will decrease the natrium phosphate cotransport 2a& 2c on renal tubules what lead to more phosphat loss.
    Together have synergetic effect.

    But on 1alpha hydroxylase they have antagonistic effects.
    – fgf23 will inhibit this enzyme what lead to decreased 1,25OH Vitamin D level.
    – PTH will activate 1alpha hydroxylase what lead to increased 1,25 OH level .
    Calcitriol will exercise his negative feedback on Parathyroid gland throw VDR receptors and decreasing his transcription.

  • Weam El Nazer


    The production of calcitriol is decreased when 1–hydroxylase is inhibited by FGF23, but PTH promotes the production of 1-hydroxylase, which results in an increase in the amount of calcitriol that is produced.

    The tubular impact that FGF23 has is caused by its binding to its Klotho co-receptor and the activation of its FGFR-1 and FGFR-3 receptors, while the tubular effect that PTH has is caused by its binding to its particular receptor.

    By decreasing the concentration of the sodium cotransporters NaPi2a and NaPi2c, both of these things contribute to an increase in the excretion of phosphate through pathways that are reliant on protein kinases A and C.

  • Israa Hammoodi


    The FGF23 will causes decrease activity of 1 alfa hydrxylase which lead to decrease in calcitriol synthesis while PTH increase synthesis and activity of 1 alfa hydrxylase so increasing the synthesis of calcitriol.
    Both FGF23 and PTH causes phosphoturia, FGF23 exert it’s effect through tubular Receptor klotho co transporter FGFR1 and FGFR3 while PTH will bind to its Receptor, both of them causes decrease in sodium phosphate cotransporter NaPi2a and NaPi2c through protein kinase A and C
    So increase phosphote excretion to normalize s. Phosphate level

  • KAMAL ELGORASHI


    The effects of FGF23 and PTH on phosphate and calcitriol:
    Parallel effects:
    Increases renal phosphate excreesion== phosphaturia, by reducing;

    • NaPi2a.
    • NaPi2c.

    Co-transporter, through protein kinase A and C -dependant pathways.
    Opposite effects:

    • FGF23 inhibits 1-alpha-hydroxylase by decreasing the synthesis of calcitriol.
    • FGF23 exerts its tubular effect via the Kloth co-receptor and activates its FGFR-1 and FGFR-3 receptors.
    • PTH stimulates the production of 1-alpha-hydroxylase, increasing calcitriol synthesis.
    • PTH binds to its specific receptor.

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