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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-4-11
pubmed:abstractText
Alkaline phosphatase activity in rat hepatoma cells (R-Y121B) cultured in a monolayer at 0.5% serum was enhanced by serum, bovine serum albumin, casein and gamma-globulin, but ovalbumin, polyvinylpyrrolidone, dexamethasone, insulin and dibutyrylcyclic AMP showed little effect on alkaline phosphatase activity. In addition, cycloheximide, actinomycin D, chloroquine, dinitrophenol and potassium cyanide also increased the enzyme activity, although the incorporation of [14C]leucine into cellular proteins was almost completely inhibited in the presence of these cytotoxic substances. When R-Y121B cell homogenates were incubated at 37 degrees C, alkaline phosphatase activity increased in a pH-dependent manner: the maximal increase was observed at pH 7.1. The magnitudes of the increase differed among cell homogenates and a 4- to 10-fold increase was observed. Alkaline phosphatase in R-Y121B cells was apparently heat-stable, but that in the cells obtained from various treatments was heat labile and the latter activity decreased to less than 50% of the initial activity after 15 min of incubation at 56 degrees C. Alkaline phosphatase in the control and also in the treated cells was more sensitive to L-homoarginine than L-phenylalanine. The Lineweaver-Burk plot showed that the increases in the enzyme activity were accompanied by changes not only in V but also in Km for alkaline phosphatase reaction. Finally, it has been suggested that the increases in alkaline phosphatase activity under various conditions are due to the conversion of the molecule with a low enzyme activity to the molecule with a high enzyme activity in R-Y121B cells.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
14
pubmed:volume
885
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
272-81
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:2418885-Alkaline Phosphatase, pubmed-meshheading:2418885-Animals, pubmed-meshheading:2418885-Blood, pubmed-meshheading:2418885-Blood Proteins, pubmed-meshheading:2418885-Cell Line, pubmed-meshheading:2418885-Chloroquine, pubmed-meshheading:2418885-Cycloheximide, pubmed-meshheading:2418885-Dactinomycin, pubmed-meshheading:2418885-Dinitrophenols, pubmed-meshheading:2418885-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:2418885-Homoarginine, pubmed-meshheading:2418885-Hot Temperature, pubmed-meshheading:2418885-Hydrogen-Ion Concentration, pubmed-meshheading:2418885-Kinetics, pubmed-meshheading:2418885-Liver Neoplasms, Experimental, pubmed-meshheading:2418885-Phenylalanine, pubmed-meshheading:2418885-Potassium Cyanide, pubmed-meshheading:2418885-Protein Biosynthesis, pubmed-meshheading:2418885-Rats
pubmed:year
1986
pubmed:articleTitle
Regulation of alkaline phosphatase activity in rat hepatoma cells. Effects of serum proteins, cycloheximide, actinomycin D, chloroquine, dinitrophenol and potassium cyanide.
pubmed:publicationType
Journal Article