Effect of starvation and diabetes on the sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate

T. W. Stephens, Robert Harris

Research output: Contribution to journalArticle

13 Citations (Scopus)

Abstract

The sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate was decreased markedly in liver mitochondria isolated from either 48 h-starved or streptozotocin-diabetic rats. These treatments of the rat also decreased the sensitivity of fatty acid oxidation by isolated hepatocytes to inhibition by this compound. Furthermore, incubation of hepatocytes prepared from fed rats with N6O2'-dibutyryl cyclic AMP also decreased the sensitivity, whereas incubation of hepatocytes prepared from starved rats with lactate plus pyruvate had the opposite effect on 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation. The sensitivity of carnitine palmitoyltransferase I of mitochondria to 4-hydroxyphenylglyoxylate increased in a time-dependent manner, as previously reported for malonyl-CoA. Likewise, oleoyl-CoA activated carnitine palmitoyltransferase I in a time-dependent manner and prevented the sensitization by 4-hydroxyphenylglyoxylate. Increased exogenous carnitine caused a moderate increase in fatty acid oxidation by hepatocytes under some conditions and a decreased 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation at low oleate concentration, without decreasing the difference in 4-hydroxyphenylglyoxylate inhibition between fed- and starved-rat hepatocytes. Time-dependent changes in the conformation of carnitine palmitoyltransferase I or the membrane environment may be involved in differences among nutritional states in 4-hydroxyphenylglyoxylate-sensitivity of carnitine palmitoyltransferase I.

Original languageEnglish
Pages (from-to)405-412
Number of pages8
JournalBiochemical Journal
Volume243
Issue number2
StatePublished - 1987

Fingerprint

Carnitine O-Palmitoyltransferase
Medical problems
Starvation
Rats
Hepatocytes
Fatty Acids
Oxidation
Mitochondria
Malonyl Coenzyme A
Bucladesine
Carnitine
Liver Mitochondrion
Oleic Acid
Streptozocin
4-hydroxyphenylglyoxylic acid
Pyruvic Acid
Liver
Conformations
Lactic Acid
Membranes

ASJC Scopus subject areas

  • Biochemistry

Cite this

Effect of starvation and diabetes on the sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate. / Stephens, T. W.; Harris, Robert.

In: Biochemical Journal, Vol. 243, No. 2, 1987, p. 405-412.

Research output: Contribution to journalArticle

@article{e14b8d2206784c198bb322b1467e2b76,
title = "Effect of starvation and diabetes on the sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate",
abstract = "The sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate was decreased markedly in liver mitochondria isolated from either 48 h-starved or streptozotocin-diabetic rats. These treatments of the rat also decreased the sensitivity of fatty acid oxidation by isolated hepatocytes to inhibition by this compound. Furthermore, incubation of hepatocytes prepared from fed rats with N6O2'-dibutyryl cyclic AMP also decreased the sensitivity, whereas incubation of hepatocytes prepared from starved rats with lactate plus pyruvate had the opposite effect on 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation. The sensitivity of carnitine palmitoyltransferase I of mitochondria to 4-hydroxyphenylglyoxylate increased in a time-dependent manner, as previously reported for malonyl-CoA. Likewise, oleoyl-CoA activated carnitine palmitoyltransferase I in a time-dependent manner and prevented the sensitization by 4-hydroxyphenylglyoxylate. Increased exogenous carnitine caused a moderate increase in fatty acid oxidation by hepatocytes under some conditions and a decreased 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation at low oleate concentration, without decreasing the difference in 4-hydroxyphenylglyoxylate inhibition between fed- and starved-rat hepatocytes. Time-dependent changes in the conformation of carnitine palmitoyltransferase I or the membrane environment may be involved in differences among nutritional states in 4-hydroxyphenylglyoxylate-sensitivity of carnitine palmitoyltransferase I.",
author = "Stephens, {T. W.} and Robert Harris",
year = "1987",
language = "English",
volume = "243",
pages = "405--412",
journal = "Biochemical Journal",
issn = "0264-6021",
publisher = "Portland Press Ltd.",
number = "2",

}

TY - JOUR

T1 - Effect of starvation and diabetes on the sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate

AU - Stephens, T. W.

AU - Harris, Robert

PY - 1987

Y1 - 1987

N2 - The sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate was decreased markedly in liver mitochondria isolated from either 48 h-starved or streptozotocin-diabetic rats. These treatments of the rat also decreased the sensitivity of fatty acid oxidation by isolated hepatocytes to inhibition by this compound. Furthermore, incubation of hepatocytes prepared from fed rats with N6O2'-dibutyryl cyclic AMP also decreased the sensitivity, whereas incubation of hepatocytes prepared from starved rats with lactate plus pyruvate had the opposite effect on 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation. The sensitivity of carnitine palmitoyltransferase I of mitochondria to 4-hydroxyphenylglyoxylate increased in a time-dependent manner, as previously reported for malonyl-CoA. Likewise, oleoyl-CoA activated carnitine palmitoyltransferase I in a time-dependent manner and prevented the sensitization by 4-hydroxyphenylglyoxylate. Increased exogenous carnitine caused a moderate increase in fatty acid oxidation by hepatocytes under some conditions and a decreased 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation at low oleate concentration, without decreasing the difference in 4-hydroxyphenylglyoxylate inhibition between fed- and starved-rat hepatocytes. Time-dependent changes in the conformation of carnitine palmitoyltransferase I or the membrane environment may be involved in differences among nutritional states in 4-hydroxyphenylglyoxylate-sensitivity of carnitine palmitoyltransferase I.

AB - The sensitivity of carnitine palmitoyltransferase I to inhibition by 4-hydroxyphenylglyoxylate was decreased markedly in liver mitochondria isolated from either 48 h-starved or streptozotocin-diabetic rats. These treatments of the rat also decreased the sensitivity of fatty acid oxidation by isolated hepatocytes to inhibition by this compound. Furthermore, incubation of hepatocytes prepared from fed rats with N6O2'-dibutyryl cyclic AMP also decreased the sensitivity, whereas incubation of hepatocytes prepared from starved rats with lactate plus pyruvate had the opposite effect on 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation. The sensitivity of carnitine palmitoyltransferase I of mitochondria to 4-hydroxyphenylglyoxylate increased in a time-dependent manner, as previously reported for malonyl-CoA. Likewise, oleoyl-CoA activated carnitine palmitoyltransferase I in a time-dependent manner and prevented the sensitization by 4-hydroxyphenylglyoxylate. Increased exogenous carnitine caused a moderate increase in fatty acid oxidation by hepatocytes under some conditions and a decreased 4-hydroxyphenylglyoxylate inhibition of fatty acid oxidation at low oleate concentration, without decreasing the difference in 4-hydroxyphenylglyoxylate inhibition between fed- and starved-rat hepatocytes. Time-dependent changes in the conformation of carnitine palmitoyltransferase I or the membrane environment may be involved in differences among nutritional states in 4-hydroxyphenylglyoxylate-sensitivity of carnitine palmitoyltransferase I.

UR - http://www.scopus.com/inward/record.url?scp=0023221166&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0023221166&partnerID=8YFLogxK

M3 - Article

C2 - 2820379

AN - SCOPUS:0023221166

VL - 243

SP - 405

EP - 412

JO - Biochemical Journal

JF - Biochemical Journal

SN - 0264-6021

IS - 2

ER -