Document Detail


Activation of liver carnitine palmitoyltransferase-1 and mitochondrial acetoacetyl-CoA thiolase is associated with elevated ketone body levels in the elasmobranch Squalus acanthias.
MedLine Citation:
PMID:  16927236     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Elasmobranch fishes are an ancient group of vertebrates that have unusual lipid metabolism whereby storage lipids are mobilized from the liver for peripheral oxidation largely as ketone bodies rather than as nonesterified fatty acids under normal conditions. This reliance on ketones, even when feeding, implies that elasmobranchs are chronically ketogenic. Compared to specimens sampled within 2 d of capture (recently captured), spiny dogfish Squalus acanthias that were held for 16-33 d without apparent feeding displayed a 4.5-fold increase in plasma concentration of d- beta -hydroxybutyrate (from 0.71 to 3.2 mM) and were considered ketotic. Overt activity of carnitine palmitoyltransferase-1 in liver mitochondria from ketotic dogfish was characterized by an increased apparent maximal activity, a trend of increasing affinity (reduced apparent K(m); P=0.09) for l-carnitine, and desensitization to the inhibitor malonyl-CoA relative to recently captured animals. Acetoacetyl-CoA thiolase (ACoAT) activity in isolated liver mitochondria was also markedly increased in the ketotic dogfish compared to recently captured fish, whereas no difference in 3-hydroxy-3-methylglutaryl-CoA synthase activity was found between these groups, suggesting that ACoAT plays a more important role in the activation of ketogenesis in spiny dogfish than in mammals and birds.
Authors:
Jason R Treberg; Elizabeth L Crockett; William R Driedzic
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Publication Detail:
Type:  Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, Non-P.H.S.     Date:  2006-08-18
Journal Detail:
Title:  Physiological and biochemical zoology : PBZ     Volume:  79     ISSN:  1522-2152     ISO Abbreviation:  Physiol. Biochem. Zool.     Publication Date:    2006 Sep-Oct
Date Detail:
Created Date:  2006-08-23     Completed Date:  2006-11-28     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  100883369     Medline TA:  Physiol Biochem Zool     Country:  United States    
Other Details:
Languages:  eng     Pagination:  899-908     Citation Subset:  IM    
Affiliation:
Ocean Sciences Centre, Memorial University of Newfoundland, St. John's, Newfoundland A1C 5S7, Canada. jtreberg@mun.ca
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MeSH Terms
Descriptor/Qualifier:
3-Hydroxybutyric Acid / metabolism
Acetyl-CoA C-Acetyltransferase / metabolism*
Animals
Brain / metabolism
Carnitine O-Palmitoyltransferase / metabolism*
Enzyme Activation
Hydroxybutyrate Dehydrogenase / metabolism
Ketone Bodies / metabolism*
Liver / enzymology*
Mitochondria / enzymology*
Myocardium / metabolism
Squalus acanthias / metabolism*
Chemical
Reg. No./Substance:
0/Ketone Bodies; 300-85-6/3-Hydroxybutyric Acid; EC 1.1.1.30/Hydroxybutyrate Dehydrogenase; EC 2.3.1.21/Carnitine O-Palmitoyltransferase; EC 2.3.1.9/Acetyl-CoA C-Acetyltransferase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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