Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2006-8-10
pubmed:abstractText
Insulin regulates hepatic VLDL production by activation of phosphatidylinositide 3-kinase (PI3-kinase) which decreases apo B available for lipid assembly. The current study evaluated the dependence of the VLDL apolipoprotein B (apo B) pathway on PI3-kinase activity in vivo. VLDL production was examined in B100 only, apo B mRNA editing catalytic subunit 1 (apobec-1(-/-)) mice, using the Triton WR 1339 method. Glucose injection suppressed VLDL triglyceride production by 28% in male and by 32% in female mice compared with saline-injected controls. When wortmannin was injected to inhibit PI3-kinase, VLDL triglyceride production was increased by 52% in males and by 89% in females, and VLDL B100 levels paralleled triglyceride changes. Pulse-chase experiments in primary mouse hepatocytes showed that wortmannin increased net freshly synthesized B100 availability by >35%. To test whether physiological insulin resistance produced equivalent effects to wortmannin, we studied male apobec-1(-/-) mice who became hyperlipidemic on being fed a fructose-enriched diet. Fructose-fed apobec-1(-/-) mice had significantly higher VLDL triglyceride and B100 production rates compared with chow-fed mice, and rates were refractile to glucose or wortmannin. Hepatic VLDL triglyceride and B100 production in wortmannin-injected chow-fed mice equaled that observed in fructose-fed mice. Together, results suggest in vivo and in vitro that wortmannin-sensitive PI3-kinases maintain a basal level of VLDL suppression that is sensitive to changes in activation and that can increase VLDL production when PI3-kinase is inhibited to levels similar to those induced by insulin resistance.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0193-1857
pubmed:author
pubmed:issnType
Print
pubmed:volume
291
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
G382-8
pubmed:dateRevised
2011-2-21
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
PI3-kinase activity modulates apo B available for hepatic VLDL production in apobec-1-/- mice.
pubmed:affiliation
Dept. of Pathology and Laboratory Medicine, Univ. of Rochester School of Medicine & Dentistry, P.O. Box 626, 601 Elmwood Ave., Rochester, New York 14642, USA.
pubmed:publicationType
Journal Article, Research Support, N.I.H., Extramural