Human peripheral blood mononuclear cells: Inhibition of biotin transport by reversible competition with pantothenic acid is quantitatively minor

Janos Zempleni, Donald M. Mock

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

A transporter present in intestinal cells and in choriocarcinoma cells has been shown to transport both pantothenic acid and biotin at similar transporter affinities. However, the concentration of pantothenic acid in most foods and biological fluids is approximately 200 times the concentration of biotin; theoretically, pantothenic acid might substantially reduce biotin transport via competition. In the present study, we sought to determine whether pantothenic acid reduces biotin transport by the biotin transporter in peripheral blood mononuclear cells (PBMC). PBMC were isolated from human blood by gradient centrifugation. Incubations with [3H]biotin and pantothenic acid were conducted at physiologic concentrations. Intracellular [3H]biotin was quantified after washing by liquid scintillation counting. Pantothenic acid at 10 to 1,000 nmol/L reduced biotin (475 pmol/L) uptake by less than 12% (P < 0.05). Based on Lineweaver-Burk plots, the competition was reversible. Several structural analogs of pantothenic acid at 1,000 nmol/L reduced biotin transport by only 7 to 15% (P = 0.13). No pattern of molecular structure required for recognition by the transporter was apparent. Extracellular pantothenic acid did not affect biotin efflux from [3H]biotin-loaded PBMC (P > 0.05), suggesting that countertransport of extracellular pantothenic acid and intracellular biotin does not increase biotin efflux from PBMC. We conclude that the physiologic effects of pantothenic acid on the transport of biotin in PBMC are likely to be quantitatively minor. Copyright (C) 1999 Elsevier Science Inc.

Original languageEnglish (US)
Pages (from-to)427-432
Number of pages6
JournalJournal of Nutritional Biochemistry
Volume10
Issue number7
DOIs
StatePublished - Jul 1 1999

Fingerprint

Pantothenic Acid
Biotin
Blood Cells
Blood
Scintillation Counting
Choriocarcinoma
Centrifugation
Scintillation
Washing

Keywords

  • Biotin
  • Human
  • Pantothenic acid
  • Peripheral blood mononuclear cells
  • Transport

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Biochemistry
  • Molecular Biology
  • Nutrition and Dietetics
  • Clinical Biochemistry

Cite this

@article{ea29ed8e91bb4c9d9ecd419f2085f23f,
title = "Human peripheral blood mononuclear cells: Inhibition of biotin transport by reversible competition with pantothenic acid is quantitatively minor",
abstract = "A transporter present in intestinal cells and in choriocarcinoma cells has been shown to transport both pantothenic acid and biotin at similar transporter affinities. However, the concentration of pantothenic acid in most foods and biological fluids is approximately 200 times the concentration of biotin; theoretically, pantothenic acid might substantially reduce biotin transport via competition. In the present study, we sought to determine whether pantothenic acid reduces biotin transport by the biotin transporter in peripheral blood mononuclear cells (PBMC). PBMC were isolated from human blood by gradient centrifugation. Incubations with [3H]biotin and pantothenic acid were conducted at physiologic concentrations. Intracellular [3H]biotin was quantified after washing by liquid scintillation counting. Pantothenic acid at 10 to 1,000 nmol/L reduced biotin (475 pmol/L) uptake by less than 12{\%} (P < 0.05). Based on Lineweaver-Burk plots, the competition was reversible. Several structural analogs of pantothenic acid at 1,000 nmol/L reduced biotin transport by only 7 to 15{\%} (P = 0.13). No pattern of molecular structure required for recognition by the transporter was apparent. Extracellular pantothenic acid did not affect biotin efflux from [3H]biotin-loaded PBMC (P > 0.05), suggesting that countertransport of extracellular pantothenic acid and intracellular biotin does not increase biotin efflux from PBMC. We conclude that the physiologic effects of pantothenic acid on the transport of biotin in PBMC are likely to be quantitatively minor. Copyright (C) 1999 Elsevier Science Inc.",
keywords = "Biotin, Human, Pantothenic acid, Peripheral blood mononuclear cells, Transport",
author = "Janos Zempleni and Mock, {Donald M.}",
year = "1999",
month = "7",
day = "1",
doi = "10.1016/S0955-2863(99)00024-8",
language = "English (US)",
volume = "10",
pages = "427--432",
journal = "Journal of Nutritional Biochemistry",
issn = "0955-2863",
publisher = "Elsevier Inc.",
number = "7",

}

TY - JOUR

T1 - Human peripheral blood mononuclear cells

T2 - Inhibition of biotin transport by reversible competition with pantothenic acid is quantitatively minor

AU - Zempleni, Janos

AU - Mock, Donald M.

PY - 1999/7/1

Y1 - 1999/7/1

N2 - A transporter present in intestinal cells and in choriocarcinoma cells has been shown to transport both pantothenic acid and biotin at similar transporter affinities. However, the concentration of pantothenic acid in most foods and biological fluids is approximately 200 times the concentration of biotin; theoretically, pantothenic acid might substantially reduce biotin transport via competition. In the present study, we sought to determine whether pantothenic acid reduces biotin transport by the biotin transporter in peripheral blood mononuclear cells (PBMC). PBMC were isolated from human blood by gradient centrifugation. Incubations with [3H]biotin and pantothenic acid were conducted at physiologic concentrations. Intracellular [3H]biotin was quantified after washing by liquid scintillation counting. Pantothenic acid at 10 to 1,000 nmol/L reduced biotin (475 pmol/L) uptake by less than 12% (P < 0.05). Based on Lineweaver-Burk plots, the competition was reversible. Several structural analogs of pantothenic acid at 1,000 nmol/L reduced biotin transport by only 7 to 15% (P = 0.13). No pattern of molecular structure required for recognition by the transporter was apparent. Extracellular pantothenic acid did not affect biotin efflux from [3H]biotin-loaded PBMC (P > 0.05), suggesting that countertransport of extracellular pantothenic acid and intracellular biotin does not increase biotin efflux from PBMC. We conclude that the physiologic effects of pantothenic acid on the transport of biotin in PBMC are likely to be quantitatively minor. Copyright (C) 1999 Elsevier Science Inc.

AB - A transporter present in intestinal cells and in choriocarcinoma cells has been shown to transport both pantothenic acid and biotin at similar transporter affinities. However, the concentration of pantothenic acid in most foods and biological fluids is approximately 200 times the concentration of biotin; theoretically, pantothenic acid might substantially reduce biotin transport via competition. In the present study, we sought to determine whether pantothenic acid reduces biotin transport by the biotin transporter in peripheral blood mononuclear cells (PBMC). PBMC were isolated from human blood by gradient centrifugation. Incubations with [3H]biotin and pantothenic acid were conducted at physiologic concentrations. Intracellular [3H]biotin was quantified after washing by liquid scintillation counting. Pantothenic acid at 10 to 1,000 nmol/L reduced biotin (475 pmol/L) uptake by less than 12% (P < 0.05). Based on Lineweaver-Burk plots, the competition was reversible. Several structural analogs of pantothenic acid at 1,000 nmol/L reduced biotin transport by only 7 to 15% (P = 0.13). No pattern of molecular structure required for recognition by the transporter was apparent. Extracellular pantothenic acid did not affect biotin efflux from [3H]biotin-loaded PBMC (P > 0.05), suggesting that countertransport of extracellular pantothenic acid and intracellular biotin does not increase biotin efflux from PBMC. We conclude that the physiologic effects of pantothenic acid on the transport of biotin in PBMC are likely to be quantitatively minor. Copyright (C) 1999 Elsevier Science Inc.

KW - Biotin

KW - Human

KW - Pantothenic acid

KW - Peripheral blood mononuclear cells

KW - Transport

UR - http://www.scopus.com/inward/record.url?scp=0033026960&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0033026960&partnerID=8YFLogxK

U2 - 10.1016/S0955-2863(99)00024-8

DO - 10.1016/S0955-2863(99)00024-8

M3 - Article

C2 - 15539319

AN - SCOPUS:0033026960

VL - 10

SP - 427

EP - 432

JO - Journal of Nutritional Biochemistry

JF - Journal of Nutritional Biochemistry

SN - 0955-2863

IS - 7

ER -