Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats

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Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats. / Zhou, A; Farver, O; Thorn, N A; Nielsen, Jens Høiriis.

I: Biochemical Journal, Bind 274 ( Pt 3), 1991, s. 739-44.

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt

Harvard

Zhou, A, Farver, O, Thorn, NA & Nielsen, JH 1991, 'Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats', Biochemical Journal, bind 274 ( Pt 3), s. 739-44.

APA

Zhou, A., Farver, O., Thorn, N. A., & Nielsen, J. H. (1991). Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats. Biochemical Journal, 274 ( Pt 3), 739-44.

Vancouver

Zhou A, Farver O, Thorn NA, Nielsen JH. Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats. Biochemical Journal. 1991;274 ( Pt 3):739-44.

Author

Zhou, A ; Farver, O ; Thorn, N A ; Nielsen, Jens Høiriis. / Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats. I: Biochemical Journal. 1991 ; Bind 274 ( Pt 3). s. 739-44.

Bibtex

@article{bb07ed0074d011dbbee902004c4f4f50,
title = "Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats",
abstract = "Several amidated biologically active peptides such as pancreastatin, thyrotropin-releasing hormone, pancreatic polypeptide and amylin are produced in endocrine pancreatic tissue which contains the enzyme necessary for their final processing, i.e. peptidylglycine alpha-amidating mono-oxygenase (EC 1.14.17.3). The enzyme needs ascorbic acid for activity as well as copper and molecular oxygen. The present work shows that pancreatic islet cells prepared from overnight cultures of isolated islets from 5-7-day-old rats accumulate 14C-labelled ascorbic acid by a Na(+)-dependent active transport mechanism which involves a saturable process (estimated Km 17.6 microM). Transport was inhibited by ouabain, phloridzin, cytochalasin B, amiloride and probenecid. Glucose inhibited or stimulated uptake, depending on the length of incubation time of the cells. The uptake of dehydroascorbic acid was linearly dependent on concentration. Dehydroascorbic acid was converted to ascorbic acid by an unknown mechanism after uptake. The uptake of both ascorbic acid and dehydroascorbic acid was inhibited by tri-iodothyronine, and uptake of ascorbic acid, but not of dehydroascorbic acid, was inhibited by glucocorticoids. Isolated secretory granules contained a fairly low concentration of iron but a high concentration of copper.",
keywords = "Animals, Animals, Newborn, Ascorbic Acid, Biological Transport, Cytoplasmic Granules, Dehydroascorbic Acid, Glucocorticoids, Glucose, Ions, Islets of Langerhans, Metals, Rats, Rats, Inbred Strains",
author = "A Zhou and O Farver and Thorn, {N A} and Nielsen, {Jens H{\o}iriis}",
year = "1991",
language = "English",
volume = "274 ( Pt 3)",
pages = "739--44",
journal = "Biochemical Journal",
issn = "0264-6021",
publisher = "Portland Press Ltd.",

}

RIS

TY - JOUR

T1 - Transport of ascorbic acid and dehydroascorbic acid by pancreatic islet cells from neonatal rats

AU - Zhou, A

AU - Farver, O

AU - Thorn, N A

AU - Nielsen, Jens Høiriis

PY - 1991

Y1 - 1991

N2 - Several amidated biologically active peptides such as pancreastatin, thyrotropin-releasing hormone, pancreatic polypeptide and amylin are produced in endocrine pancreatic tissue which contains the enzyme necessary for their final processing, i.e. peptidylglycine alpha-amidating mono-oxygenase (EC 1.14.17.3). The enzyme needs ascorbic acid for activity as well as copper and molecular oxygen. The present work shows that pancreatic islet cells prepared from overnight cultures of isolated islets from 5-7-day-old rats accumulate 14C-labelled ascorbic acid by a Na(+)-dependent active transport mechanism which involves a saturable process (estimated Km 17.6 microM). Transport was inhibited by ouabain, phloridzin, cytochalasin B, amiloride and probenecid. Glucose inhibited or stimulated uptake, depending on the length of incubation time of the cells. The uptake of dehydroascorbic acid was linearly dependent on concentration. Dehydroascorbic acid was converted to ascorbic acid by an unknown mechanism after uptake. The uptake of both ascorbic acid and dehydroascorbic acid was inhibited by tri-iodothyronine, and uptake of ascorbic acid, but not of dehydroascorbic acid, was inhibited by glucocorticoids. Isolated secretory granules contained a fairly low concentration of iron but a high concentration of copper.

AB - Several amidated biologically active peptides such as pancreastatin, thyrotropin-releasing hormone, pancreatic polypeptide and amylin are produced in endocrine pancreatic tissue which contains the enzyme necessary for their final processing, i.e. peptidylglycine alpha-amidating mono-oxygenase (EC 1.14.17.3). The enzyme needs ascorbic acid for activity as well as copper and molecular oxygen. The present work shows that pancreatic islet cells prepared from overnight cultures of isolated islets from 5-7-day-old rats accumulate 14C-labelled ascorbic acid by a Na(+)-dependent active transport mechanism which involves a saturable process (estimated Km 17.6 microM). Transport was inhibited by ouabain, phloridzin, cytochalasin B, amiloride and probenecid. Glucose inhibited or stimulated uptake, depending on the length of incubation time of the cells. The uptake of dehydroascorbic acid was linearly dependent on concentration. Dehydroascorbic acid was converted to ascorbic acid by an unknown mechanism after uptake. The uptake of both ascorbic acid and dehydroascorbic acid was inhibited by tri-iodothyronine, and uptake of ascorbic acid, but not of dehydroascorbic acid, was inhibited by glucocorticoids. Isolated secretory granules contained a fairly low concentration of iron but a high concentration of copper.

KW - Animals

KW - Animals, Newborn

KW - Ascorbic Acid

KW - Biological Transport

KW - Cytoplasmic Granules

KW - Dehydroascorbic Acid

KW - Glucocorticoids

KW - Glucose

KW - Ions

KW - Islets of Langerhans

KW - Metals

KW - Rats

KW - Rats, Inbred Strains

M3 - Journal article

VL - 274 ( Pt 3)

SP - 739

EP - 744

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

ER -

ID: 299758