Regulation of urinary phosphate excretion in camels

Riad, Fouad; Goumi, M. Ben; Davicco, Marie-Jeanne; Coxam, Véronique; Tressol, J.C.; Barlet, J.P.

doi:10.1016/0300-9629(95)00061-b

Cited by 2 publications

(5 citation statements)

References 20 publications

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“…A similar effect on circulating levels of Ca 2ϩ and decreased circulating P i was observed in PTHrP-infused camels (45). In the present study, the effects of PTHrP on Ca 2ϩ transport were particularly notable, since winter flounder renal tubule is mostly composed of proximal type II segments and lacks the distal tubule segment (16) usually associated with active Ca 2ϩ regulation in terrestrial vertebrates (30).…”

Section: Discussionsupporting

confidence: 77%

Piscine PTHrP regulation of calcium and phosphate transport in winter flounder renal proximal tubule primary cultures

Guerreiro

Canário

Power

et al. 2010

American Journal of Physiology-Regulatory, Integrative and Comp

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Multiple factors control calcium (Ca(2+)) and inorganic phosphate (P(i)) transport in the fish nephron, and the recently discovered members of the piscine parathyroid hormone-like protein family are likely participants in such regulatory mechanisms. The effects of an NH(2)-terminal peptide (amino acids 1-34) of Takifugu rubripes parathyroid hormone-related protein, (1-34)PTHrP, on Ca(2+) and P(i) transport were investigated in winter flounder (Pseudopleuronectes americanus) proximal tubule cells in primary culture (fPTCs). RT-PCR performed on RNA extracted from fPTCs and from intact kidney tissue indicated that expression of PTHrP and types 1 and 3 PTH/PTHrP receptors occurred both in vivo and in vitro and that circulating levels of PTHrP measured by specific radioimmunoassay averaged 2.5 +/- 0.13 ng/ml. fPTC monolayers were mounted in Ussing chambers, and under neutral electrochemical conditions, addition of 10 nM (1-34)PTHrP to the basolateral side induced a slight increase in Ca(2+) transport rate from luminal to peritubular side, significantly stimulating net Ca(2+) reabsorption. (1-34)PTHrP also significantly increased the P(i) secretory flux, and slightly reduced P(i) reabsorption, evoking a significant increase in P(i) net secretion. This stimulatory effect was partially inhibited by bisindolylmaleimide, an inhibitor of protein kinase C. Incubation of ex vivo flounder renal tubules with (1-34)PTHrP resulted in apparent reduction of Na(+)-P(i) cotransporter type II (NaP(i)-II) protein in tubule membranes. PTHrP seems therefore to participate in the modulation of Ca(2+) and P(i) homeostasis by fish kidney.

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Section: Discussionsupporting

confidence: 77%

Piscine PTHrP regulation of calcium and phosphate transport in winter flounder renal proximal tubule primary cultures

Guerreiro

Canário

Power

et al. 2010

American Journal of Physiology-Regulatory, Integrative and Comp

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“…Since intact FGF23 levels were not different between WT and PTH KO mice, we first examined additional phosphaturic hormones. PTHrp and dopamine induce phosphaturia in several species 25,28–30 . Whether PTHrp levels are modulated by acute changes in Pi intake has been unknown, but our data indicate no apparent response to Pi gavage in WT mice within 12 h. However, we found that PTHrp levels were significantly higher in PTH KO mice 4 h after gavage both in the saline and Pi groups, which may indicate a suppressive effect of PTH on PTHrp levels and rather regulation by other factors such as circadian rhythm in the absence of PTH.…”

Section: Discussionmentioning

confidence: 48%

“…PTHrp and dopamine induce phosphaturia in several species. 25,[28][29][30] Whether PTHrp levels are modulated by acute changes in Pi intake has been unknown, but our data indicate no apparent response to Pi gavage in WT mice within 12 h. However, we found that PTHrp levels were significantly higher in PTH KO mice 4 h after gavage both in the saline and Pi groups, which may indicate a suppressive effect of PTH on PTHrp levels and rather regulation by other Whether PTHrp is able to regulate renal Pi excretion via modulation of NaPi-IIa and/or NaPi-IIc remains to be examined. Also insulin and dopamine may be modulated by dietary Pi intake and play a role in the response.…”

Section: Discussionmentioning

confidence: 99%

“…We also found no differences in the renal abundance of the FGF23 co-receptor, α-Klotho, at any time point and in any group (Figure S3A-F). Due to a possible impact of PTHrp on renal Pi reabsorption, as reported in several species, 29,34,35 we measured the plasma levels of this hormone. PTHrp levels were not altered by Pi gavage, though 4 h after gavage differences between genotypes were observed (Figure 2G-I).…”

Section: Induction Of Pth and Fgf23 In Response To Acute Pi Gavagementioning

confidence: 99%

“…We examined also some additional phosphaturic factors such as FGF23, dopamine and PTH‐related peptide (PTHrp). The latter has been shown in several species to induce also phosphaturia 28–30 even though the exact cellular and molecular mechanisms are unknown. We also tested the role of inositol hexakisphosphate kinases, which are involved in yeast and bacteria in sensing intracellular Pi levels and adapting Pi transporters 31,32 .…”

Section: Introductionmentioning

confidence: 99%

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Acute adaptation of renal phosphate transporters in the murine kidney to oral phosphate intake requires multiple signals

et al. 2022

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Aims Dietary inorganic phosphate (Pi) modulates renal Pi reabsorption by regulating the expression of the NaPi‐IIa and NaPi‐IIc Pi transporters. Here, we aimed to clarify the role of several Pi‐regulatory mechanisms including parathyroid hormone (PTH), fibroblast growth factor 23 (FGF23) and inositol hexakisphosphate kinases (IP6‐kinases) in the acute regulation of NaPi‐IIa and NaPi‐IIc. Methods Wildtype (WT) and PTH‐deficient mice (PTH‐KO) with/without inhibition of FGF23 signalling were gavaged with Pi/saline and examined at 1, 4 and 12 h. Results Pi‐gavage elevated plasma Pi and decreased plasma Ca2+ in both genotypes after 1 h Within 1 h, Pi‐gavage decreased NaPi‐IIa abundance in WT and PTH‐KO mice. NaPi‐IIc was downregulated 1 h post‐administration in WT and after 4 h in PTH‐KO. PTH increased after 1 h in WT animals. After 4 h Pi‐gavage, FGF23 increased in both genotypes being higher in the KO group. PTHrp and dopamine were not altered by Pi‐gavage. Blocking FGF23 signalling blunted PTH upregulation in WT mice and reduced NaPi‐IIa downregulation in PTH‐KO mice 4 h after Pi‐gavage. Inhibition of IP6‐kinases had no effect. Conclusions (1) Acute downregulation of renal Pi transporters in response to Pi intake occurs also in the absence of PTH and FGF23 signalling, (2) when FGF23 signalling is blocked, a partial contribution of PTH is revealed, (3) IP6 kinases, intracellular Pi‐sensors in yeast and bacteria, are not involved, and (4) Acute Pi does not alter PTHrp and dopamine. Thus, signals other than PTH, PTHrp, FGF23 and dopamine contribute to renal adaption.

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Regulation of urinary phosphate excretion in camels

Cited by 2 publications

References 20 publications

Piscine PTHrP regulation of calcium and phosphate transport in winter flounder renal proximal tubule primary cultures

Piscine PTHrP regulation of calcium and phosphate transport in winter flounder renal proximal tubule primary cultures

Acute adaptation of renal phosphate transporters in the murine kidney to oral phosphate intake requires multiple signals

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