The effect of vitamin B6 deficiency on alanine

Glyoxylate aminotransferase isoenzymes in rat liver

Yoshikazu Takada, Toshio Mori, Tomoo Noguchi

Research output: Contribution to journalArticle

18 Citations (Scopus)

Abstract

Endogenous synthesis of oxalate has been reported to increase in vitamin B6 deficiency probably due to defective transamination of glyoxylate, the direct source of oxalate, to glycine. Alanine:glyoxylate aminotransferase (AGT) in the liver catalyzes most of the glyoxylate transamination in mammalian tissues (E. V. Rowsell, K. Snell, J. A. Carnie, and K. V. Rowsell (1972)Biochem. J.127, 155-165). The effects of vitamin B6 deficiency on hepatic AGT isoenzymes, designated AGT 1 and AGT 2, respectively, were examined with male rats; AGT 1 is located both in the peroxisomes and in the mitochondria, and AGT 2 only in the mitochondria. The holo activity of combined peroxisomal and mitochondrial AGT 1 with a low Km for l-alanine rapidly decreased after a lag time of about 2 days during feeding of the vitamin B6-deficient diet (by 50% in 5 days, by 86% in 14 days). Peroxisomal AGT 1 activity was more affected than the mitochondrial. The holo activity of AGT 2 with a high Km for l-alanine decreased more slowly than AGT 1 (by 33% in 14 days, by 60% in 28 days). Urinary excretion of oxalate began to increase in 8-9 days, when AGT 2 remained intact but most of AGT 1 is depleted. When the defect in the glyoxylate transamination in vivo in vitamin B6 deficiency is considered, these findings suggest that it is due to the deficiency of AGT 1. The importance of peroxisomal AGT 1 is discussed, since peroxisomes have been described to be probably the major site of glyoxylate formation.

Original languageEnglish (US)
Pages (from-to)1-6
Number of pages6
JournalArchives of Biochemistry and Biophysics
Volume229
Issue number1
DOIs
StatePublished - Feb 15 1984
Externally publishedYes

Fingerprint

Vitamin B 6 Deficiency
Vitamin B 6
Liver
Isoenzymes
Rats
Oxalates
Mitochondria
Peroxisomes
Alanine-glyoxylate transaminase
Alanine
Nutrition

ASJC Scopus subject areas

  • Biochemistry
  • Biophysics
  • Molecular Biology

Cite this

The effect of vitamin B6 deficiency on alanine : Glyoxylate aminotransferase isoenzymes in rat liver. / Takada, Yoshikazu; Mori, Toshio; Noguchi, Tomoo.

In: Archives of Biochemistry and Biophysics, Vol. 229, No. 1, 15.02.1984, p. 1-6.

Research output: Contribution to journalArticle

@article{dafb1dea56c1456983037a1664072d7f,
title = "The effect of vitamin B6 deficiency on alanine: Glyoxylate aminotransferase isoenzymes in rat liver",
abstract = "Endogenous synthesis of oxalate has been reported to increase in vitamin B6 deficiency probably due to defective transamination of glyoxylate, the direct source of oxalate, to glycine. Alanine:glyoxylate aminotransferase (AGT) in the liver catalyzes most of the glyoxylate transamination in mammalian tissues (E. V. Rowsell, K. Snell, J. A. Carnie, and K. V. Rowsell (1972)Biochem. J.127, 155-165). The effects of vitamin B6 deficiency on hepatic AGT isoenzymes, designated AGT 1 and AGT 2, respectively, were examined with male rats; AGT 1 is located both in the peroxisomes and in the mitochondria, and AGT 2 only in the mitochondria. The holo activity of combined peroxisomal and mitochondrial AGT 1 with a low Km for l-alanine rapidly decreased after a lag time of about 2 days during feeding of the vitamin B6-deficient diet (by 50{\%} in 5 days, by 86{\%} in 14 days). Peroxisomal AGT 1 activity was more affected than the mitochondrial. The holo activity of AGT 2 with a high Km for l-alanine decreased more slowly than AGT 1 (by 33{\%} in 14 days, by 60{\%} in 28 days). Urinary excretion of oxalate began to increase in 8-9 days, when AGT 2 remained intact but most of AGT 1 is depleted. When the defect in the glyoxylate transamination in vivo in vitamin B6 deficiency is considered, these findings suggest that it is due to the deficiency of AGT 1. The importance of peroxisomal AGT 1 is discussed, since peroxisomes have been described to be probably the major site of glyoxylate formation.",
author = "Yoshikazu Takada and Toshio Mori and Tomoo Noguchi",
year = "1984",
month = "2",
day = "15",
doi = "10.1016/0003-9861(84)90123-1",
language = "English (US)",
volume = "229",
pages = "1--6",
journal = "Archives of Biochemistry and Biophysics",
issn = "0003-9861",
publisher = "Academic Press Inc.",
number = "1",

}

TY - JOUR

T1 - The effect of vitamin B6 deficiency on alanine

T2 - Glyoxylate aminotransferase isoenzymes in rat liver

AU - Takada, Yoshikazu

AU - Mori, Toshio

AU - Noguchi, Tomoo

PY - 1984/2/15

Y1 - 1984/2/15

N2 - Endogenous synthesis of oxalate has been reported to increase in vitamin B6 deficiency probably due to defective transamination of glyoxylate, the direct source of oxalate, to glycine. Alanine:glyoxylate aminotransferase (AGT) in the liver catalyzes most of the glyoxylate transamination in mammalian tissues (E. V. Rowsell, K. Snell, J. A. Carnie, and K. V. Rowsell (1972)Biochem. J.127, 155-165). The effects of vitamin B6 deficiency on hepatic AGT isoenzymes, designated AGT 1 and AGT 2, respectively, were examined with male rats; AGT 1 is located both in the peroxisomes and in the mitochondria, and AGT 2 only in the mitochondria. The holo activity of combined peroxisomal and mitochondrial AGT 1 with a low Km for l-alanine rapidly decreased after a lag time of about 2 days during feeding of the vitamin B6-deficient diet (by 50% in 5 days, by 86% in 14 days). Peroxisomal AGT 1 activity was more affected than the mitochondrial. The holo activity of AGT 2 with a high Km for l-alanine decreased more slowly than AGT 1 (by 33% in 14 days, by 60% in 28 days). Urinary excretion of oxalate began to increase in 8-9 days, when AGT 2 remained intact but most of AGT 1 is depleted. When the defect in the glyoxylate transamination in vivo in vitamin B6 deficiency is considered, these findings suggest that it is due to the deficiency of AGT 1. The importance of peroxisomal AGT 1 is discussed, since peroxisomes have been described to be probably the major site of glyoxylate formation.

AB - Endogenous synthesis of oxalate has been reported to increase in vitamin B6 deficiency probably due to defective transamination of glyoxylate, the direct source of oxalate, to glycine. Alanine:glyoxylate aminotransferase (AGT) in the liver catalyzes most of the glyoxylate transamination in mammalian tissues (E. V. Rowsell, K. Snell, J. A. Carnie, and K. V. Rowsell (1972)Biochem. J.127, 155-165). The effects of vitamin B6 deficiency on hepatic AGT isoenzymes, designated AGT 1 and AGT 2, respectively, were examined with male rats; AGT 1 is located both in the peroxisomes and in the mitochondria, and AGT 2 only in the mitochondria. The holo activity of combined peroxisomal and mitochondrial AGT 1 with a low Km for l-alanine rapidly decreased after a lag time of about 2 days during feeding of the vitamin B6-deficient diet (by 50% in 5 days, by 86% in 14 days). Peroxisomal AGT 1 activity was more affected than the mitochondrial. The holo activity of AGT 2 with a high Km for l-alanine decreased more slowly than AGT 1 (by 33% in 14 days, by 60% in 28 days). Urinary excretion of oxalate began to increase in 8-9 days, when AGT 2 remained intact but most of AGT 1 is depleted. When the defect in the glyoxylate transamination in vivo in vitamin B6 deficiency is considered, these findings suggest that it is due to the deficiency of AGT 1. The importance of peroxisomal AGT 1 is discussed, since peroxisomes have been described to be probably the major site of glyoxylate formation.

UR - http://www.scopus.com/inward/record.url?scp=0021288775&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0021288775&partnerID=8YFLogxK

U2 - 10.1016/0003-9861(84)90123-1

DO - 10.1016/0003-9861(84)90123-1

M3 - Article

VL - 229

SP - 1

EP - 6

JO - Archives of Biochemistry and Biophysics

JF - Archives of Biochemistry and Biophysics

SN - 0003-9861

IS - 1

ER -