Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1997-2-13
pubmed:abstractText
Catecholamines are responsible for the daily changes in hepatic lipase (HL) expression associated with feeding and fasting. We have studied the mechanism by which adrenaline decreases HL secretion in suspensions of freshly isolated rat hepatocytes. Adrenaline acutely inhibited HL activity through activation of the alpha1-adrenergic pathway. The cells had significantly less HL activity in the presence of adrenaline versus cycloheximide, where protein de novo synthesis is completely blocked. The specific enzyme activity of secreted HL was not affected. Intracellular HL activity was decreased by adrenaline treatment. Pulse-labeling with [35S]methionine showed that de novo synthesis of the 53-kd endo-beta-N-acetylglucosaminidase H (Endo H)-sensitive HL protein was unaffected by adrenaline. During subsequent chase of the control cells, the 53-kd form was converted to a 58-kd Endo H-resistant HL protein, which was rapidly secreted into the medium. In the presence of adrenaline, formation of the 58-kd protein was markedly reduced, whereas the 53-kd protein disappeared at a rate similar to the rate in controls. This suggests that part of the HL protein was degraded. In contrast to adrenaline, inhibition of HL secretion by colchicine was accompanied by an intracellular accumulation of HL activity and of the 58-kd protein. We conclude that adrenaline inhibits HL secretion posttranslationally by retarding the maturation of the 53-kd HL precursor to an active 58-kd protein, possibly by stimulating degradation of newly synthesized HL protein.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0026-0495
pubmed:author
pubmed:issnType
Print
pubmed:volume
46
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
76-82
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1997
pubmed:articleTitle
Acute effects of adrenaline on hepatic lipase secretion by rat hepatocytes.
pubmed:affiliation
Department of Biochemistry, Erasmus University Rotterdam, The Netherlands.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't