Dietary phosphorus regulates intestinal transport and plasma concentrations of phosphate in rainbow trout

E. M. Avila, H. Tu, S. Basantes, Ronaldo Ferraris

Research output: Contribution to journalArticle

47 Citations (Scopus)

Abstract

Intestinal inorganic phosphate transport and its regulation have not been studied in fish. In this study, we initially characterized the mechanisms of intestinal inorganic phosphate transport in rainbow trout (Oncorhynchus mykiss) then determined the effects of dietary phosphorus concentrations on intestinal inorganic phosphate uptake, plasma inorganic phosphate, and intestinal luminal inorganic phosphate concentrations. In 11-g trout, the saturable mechanism of brushborder inorganic phosphate uptake had a K(t) = 1.2 mmol l-1 and a V(max) = 0.22 nmol mg-1 min-1, while the diffusive component had a K(d) = 0.012 min-1. Similar kinetic constants were obtained from 51-g trout, suggesting that development or size had little effect on transport. Tracer inorganic phosphate (1.18 mmol l-1) uptake was almost completely inhibited (>95%) by 20 mmol l-1 unlabeled inorganic phosphate. Inorganic phosphate uptake (0.2 mmol l-1) was strongly inhibited (~75% inhibition) by phosphonoformic acid, a competitive inhibitor of mammalian inorganic phosphate transport, as well as by the absence of Na+ (~90% inhibition). Northern blot and reverse transcription-polymerase chain reaction indicated that the intestinal inorganic phosphate transporter in trout is not related to the cloned Na+ inorganic phosphate-II transporter of winter flounder. Intestinal luminal and plasma inorganic phosphate concentrations each increased with dietary P concentrations. Intestinal inorganic phosphate, but not proline, absorption rates decreased with dietary phosphorus concentrations. As in mammals and birds, a Na-dependent inorganic phosphate carrier that is tightly regulated by diet is present in trout small intestine.

Original languageEnglish (US)
Pages (from-to)201-209
Number of pages9
JournalJournal of Comparative Physiology - B Biochemical, Systemic, and Environmental Physiology
Volume170
Issue number3
DOIs
StatePublished - Jan 1 2000

Fingerprint

Dietary Phosphorus
phosphate (inorganic)
Oncorhynchus mykiss
rainbow
Phosphates
phosphate
phosphates
phosphorus
Plasmas
plasma
Trout
Phosphate Transport Proteins
trout
transporters
Foscarnet
Flounder
Pseudopleuronectes americanus
Mammals
Polymerase chain reaction
Birds

All Science Journal Classification (ASJC) codes

  • Physiology
  • Ecology, Evolution, Behavior and Systematics
  • Biochemistry
  • Animal Science and Zoology
  • Endocrinology

Cite this

@article{9b8918953b4047ec894259d2460ff5f5,
title = "Dietary phosphorus regulates intestinal transport and plasma concentrations of phosphate in rainbow trout",
abstract = "Intestinal inorganic phosphate transport and its regulation have not been studied in fish. In this study, we initially characterized the mechanisms of intestinal inorganic phosphate transport in rainbow trout (Oncorhynchus mykiss) then determined the effects of dietary phosphorus concentrations on intestinal inorganic phosphate uptake, plasma inorganic phosphate, and intestinal luminal inorganic phosphate concentrations. In 11-g trout, the saturable mechanism of brushborder inorganic phosphate uptake had a K(t) = 1.2 mmol l-1 and a V(max) = 0.22 nmol mg-1 min-1, while the diffusive component had a K(d) = 0.012 min-1. Similar kinetic constants were obtained from 51-g trout, suggesting that development or size had little effect on transport. Tracer inorganic phosphate (1.18 mmol l-1) uptake was almost completely inhibited (>95{\%}) by 20 mmol l-1 unlabeled inorganic phosphate. Inorganic phosphate uptake (0.2 mmol l-1) was strongly inhibited (~75{\%} inhibition) by phosphonoformic acid, a competitive inhibitor of mammalian inorganic phosphate transport, as well as by the absence of Na+ (~90{\%} inhibition). Northern blot and reverse transcription-polymerase chain reaction indicated that the intestinal inorganic phosphate transporter in trout is not related to the cloned Na+ inorganic phosphate-II transporter of winter flounder. Intestinal luminal and plasma inorganic phosphate concentrations each increased with dietary P concentrations. Intestinal inorganic phosphate, but not proline, absorption rates decreased with dietary phosphorus concentrations. As in mammals and birds, a Na-dependent inorganic phosphate carrier that is tightly regulated by diet is present in trout small intestine.",
author = "Avila, {E. M.} and H. Tu and S. Basantes and Ronaldo Ferraris",
year = "2000",
month = "1",
day = "1",
doi = "10.1007/s003600050276",
language = "English (US)",
volume = "170",
pages = "201--209",
journal = "Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology",
issn = "0174-1578",
publisher = "Springer Verlag",
number = "3",

}

TY - JOUR

T1 - Dietary phosphorus regulates intestinal transport and plasma concentrations of phosphate in rainbow trout

AU - Avila, E. M.

AU - Tu, H.

AU - Basantes, S.

AU - Ferraris, Ronaldo

PY - 2000/1/1

Y1 - 2000/1/1

N2 - Intestinal inorganic phosphate transport and its regulation have not been studied in fish. In this study, we initially characterized the mechanisms of intestinal inorganic phosphate transport in rainbow trout (Oncorhynchus mykiss) then determined the effects of dietary phosphorus concentrations on intestinal inorganic phosphate uptake, plasma inorganic phosphate, and intestinal luminal inorganic phosphate concentrations. In 11-g trout, the saturable mechanism of brushborder inorganic phosphate uptake had a K(t) = 1.2 mmol l-1 and a V(max) = 0.22 nmol mg-1 min-1, while the diffusive component had a K(d) = 0.012 min-1. Similar kinetic constants were obtained from 51-g trout, suggesting that development or size had little effect on transport. Tracer inorganic phosphate (1.18 mmol l-1) uptake was almost completely inhibited (>95%) by 20 mmol l-1 unlabeled inorganic phosphate. Inorganic phosphate uptake (0.2 mmol l-1) was strongly inhibited (~75% inhibition) by phosphonoformic acid, a competitive inhibitor of mammalian inorganic phosphate transport, as well as by the absence of Na+ (~90% inhibition). Northern blot and reverse transcription-polymerase chain reaction indicated that the intestinal inorganic phosphate transporter in trout is not related to the cloned Na+ inorganic phosphate-II transporter of winter flounder. Intestinal luminal and plasma inorganic phosphate concentrations each increased with dietary P concentrations. Intestinal inorganic phosphate, but not proline, absorption rates decreased with dietary phosphorus concentrations. As in mammals and birds, a Na-dependent inorganic phosphate carrier that is tightly regulated by diet is present in trout small intestine.

AB - Intestinal inorganic phosphate transport and its regulation have not been studied in fish. In this study, we initially characterized the mechanisms of intestinal inorganic phosphate transport in rainbow trout (Oncorhynchus mykiss) then determined the effects of dietary phosphorus concentrations on intestinal inorganic phosphate uptake, plasma inorganic phosphate, and intestinal luminal inorganic phosphate concentrations. In 11-g trout, the saturable mechanism of brushborder inorganic phosphate uptake had a K(t) = 1.2 mmol l-1 and a V(max) = 0.22 nmol mg-1 min-1, while the diffusive component had a K(d) = 0.012 min-1. Similar kinetic constants were obtained from 51-g trout, suggesting that development or size had little effect on transport. Tracer inorganic phosphate (1.18 mmol l-1) uptake was almost completely inhibited (>95%) by 20 mmol l-1 unlabeled inorganic phosphate. Inorganic phosphate uptake (0.2 mmol l-1) was strongly inhibited (~75% inhibition) by phosphonoformic acid, a competitive inhibitor of mammalian inorganic phosphate transport, as well as by the absence of Na+ (~90% inhibition). Northern blot and reverse transcription-polymerase chain reaction indicated that the intestinal inorganic phosphate transporter in trout is not related to the cloned Na+ inorganic phosphate-II transporter of winter flounder. Intestinal luminal and plasma inorganic phosphate concentrations each increased with dietary P concentrations. Intestinal inorganic phosphate, but not proline, absorption rates decreased with dietary phosphorus concentrations. As in mammals and birds, a Na-dependent inorganic phosphate carrier that is tightly regulated by diet is present in trout small intestine.

UR - http://www.scopus.com/inward/record.url?scp=0034087085&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0034087085&partnerID=8YFLogxK

U2 - 10.1007/s003600050276

DO - 10.1007/s003600050276

M3 - Article

VL - 170

SP - 201

EP - 209

JO - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology

JF - Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology

SN - 0174-1578

IS - 3

ER -