Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1985-11-20
pubmed:abstractText
Primary monolayer cultures of adult rat hepatocytes can be induced to undergo DNA synthesis in serum-free medium in the presence of insulin, glucagon, and epidermal growth factor (three factors). We have found that hepatocyte DNA synthesis is affected not only by an endogenous stimulant produced by the hepatocytes and released into the culture medium. Serum has a strong inhibitory effect on hepatocyte DNA synthesis. Partially purified human platelet extract ("platelet inhibitor") inhibits the three-factor-induced DNA synthesis in a concentration-dependent manner. Pure beta TGF at 0.5 ng/ml as well as HPLC-purified PDGF at 10 ng/ml completely inhibit the three-factor-induced DNA synthesis. Determination of the time required for the presence of the three factors and the platelet inhibitor to exert their effects indicated that the inhibition of DNA synthesis is caused not by competition of the platelet inhibitor with any of the three factors but through an independent pathway. Hepatocyte DNA synthesis is density-dependent and is greater if medium is not changed during the course of an experiment than if medium is changed daily. Hepatocyte-conditioned medium is also affective in stimulating DNA synthesis beyond the level induced by the three factors. These results suggest that an endogenous stimulant for hepatocyte DNA synthesis is produced by the hepatocytes themselves. Our studies demonstrate that hepatocyte DNA synthesis is subject to both stimulatory and inhibitory controls. Unlike the three factors, the endogenous stimulant can overcome the inhibition by the platelet inhibitor, suggesting the importance of these factors in the physiological control of hepatocyte DNA synthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9541
pubmed:author
pubmed:issnType
Print
pubmed:volume
125
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
82-90
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:3900103-Animals, pubmed-meshheading:3900103-Blood, pubmed-meshheading:3900103-Blood Platelets, pubmed-meshheading:3900103-Centrifugation, Density Gradient, pubmed-meshheading:3900103-Chromatography, High Pressure Liquid, pubmed-meshheading:3900103-Culture Media, pubmed-meshheading:3900103-DNA Replication, pubmed-meshheading:3900103-Dose-Response Relationship, Drug, pubmed-meshheading:3900103-Epidermal Growth Factor, pubmed-meshheading:3900103-Glucagon, pubmed-meshheading:3900103-Insulin, pubmed-meshheading:3900103-Liver, pubmed-meshheading:3900103-Male, pubmed-meshheading:3900103-Peptides, pubmed-meshheading:3900103-Platelet-Derived Growth Factor, pubmed-meshheading:3900103-Rats, pubmed-meshheading:3900103-Rats, Inbred F344, pubmed-meshheading:3900103-Time Factors, pubmed-meshheading:3900103-Transforming Growth Factors
pubmed:year
1985
pubmed:articleTitle
DNA synthesis in rat hepatocytes: inhibition by a platelet factor and stimulation by an endogenous factor.
pubmed:publicationType
Journal Article