Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
10
pubmed:dateCreated
1975-7-24
pubmed:abstractText
Receptors for insulin and epidermal growth factor (EGF) have been studied in confluent cultured intact human fibroblast monolayers. 125-I-EGF binds specifically to fibroblast monolayers. Half-maximal binding is observed at 4 times 10 minus 10 M EGF; at saturation of binding approximately 4 times 10-4 molecules of EGF are bound per cell. 125-I-Insulin is also bound specifically by intact monolayers with half-maximal binding observed at 10 minus 9 M insulin; about 4 times 10-3 molecules of insulin are bound per cell at saturation. Both insulin and EGF stimulate thymidine incorporation and alpha-aminoisobutyrate uptake. A half-maximal effect for insulin is observed at about 10 minus 9 M, both for the stimulation of thymidine incorporation and for the stimulation of alpha-aminoisobutyrate uptake; for EGF, half-maximal stimulation of both thymidine incorporation and alpha-aminoisobutyrate uptake is observed at 10 minus 10 M EGF. EGF causes an apparent greater stimulation of thymidine incorporation than does insulin, whereas the stimulation of alpha-aminoisobutyrate uptake is the same for both insulin and EGF. The degree of stimulation of alpha-aminoisobutyrate uptake by either insulin or EGF varied (1.2- to 2-fold) from one batch of cells to another, as did the measured values of the apparent K-m (average value 1 mM, range 0.6 to 2 mM) and V-max (average, 0.82, range 0.78 to 0.87 nmol/100 mug of protein per min) for alpha-aminoisobutyrate. Nonetheless, the apparent K-m of each peptide for stimulation of alpha-aminoisobutyrate uptake was independent of the degree of increase in alpha-aminoisobutyrate uptake, and was constant from one batch of cells to another. The peptide-mediated stimulation of alpha-aminoisobutyrate uptake can be attributed to a decrease in the apparent K-m for alpha-aminoisobutyrate (e.g. for insulin) from 0.70 to 0.57 mM; for EGF from 0.87 to 0.66 mM) and a concomitant increase in the apparent V-max for alpha-aminoisobutyrate (e.g. for insulin from 0.78 to 0.87 and for EGF from 0.80 to 0.84 nmol/min/100 mug of cell protein). The stimulation requires a 40- to 60-min period of preincubation with either peptide and is blocked by pretreating cells with cycloheximide. In the presence of ouabain, both peptides inhibit rather than stimulate alpha-aminoisobutyrate uptake; ouabain lowers the basal rate of alpha-aminoisobutyrate uptake. The uptake of 3-0-methyl-D-glucose is not affected by either EGF or insulin under conditions where insulin stimulates fat cell transport. These observations indicate that cultured human fibroblasts possess specific binding sites for insulin and EGF, which sites can be related to two actions of the peptides: stimulation of thymidine incorporation and alpha-aminoisobutyrate uptake.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Adrenocorticotropic Hormone, http://linkedlifedata.com/resource/pubmed/chemical/Aminoisobutyric Acids, http://linkedlifedata.com/resource/pubmed/chemical/Cycloheximide, http://linkedlifedata.com/resource/pubmed/chemical/DNA, http://linkedlifedata.com/resource/pubmed/chemical/Glucagon, http://linkedlifedata.com/resource/pubmed/chemical/Growth Substances, http://linkedlifedata.com/resource/pubmed/chemical/Insulin, http://linkedlifedata.com/resource/pubmed/chemical/Lectins, http://linkedlifedata.com/resource/pubmed/chemical/Ouabain, http://linkedlifedata.com/resource/pubmed/chemical/Puromycin, http://linkedlifedata.com/resource/pubmed/chemical/Receptors, Cell Surface, http://linkedlifedata.com/resource/pubmed/chemical/Thymidine, http://linkedlifedata.com/resource/pubmed/chemical/Vasopressins
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3845-53
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:165185-Adrenocorticotropic Hormone, pubmed-meshheading:165185-Aminoisobutyric Acids, pubmed-meshheading:165185-Biological Transport, pubmed-meshheading:165185-Cells, Cultured, pubmed-meshheading:165185-Cycloheximide, pubmed-meshheading:165185-DNA, pubmed-meshheading:165185-Fibroblasts, pubmed-meshheading:165185-Glucagon, pubmed-meshheading:165185-Growth Substances, pubmed-meshheading:165185-Humans, pubmed-meshheading:165185-Insulin, pubmed-meshheading:165185-Kinetics, pubmed-meshheading:165185-Lectins, pubmed-meshheading:165185-Ouabain, pubmed-meshheading:165185-Protein Binding, pubmed-meshheading:165185-Puromycin, pubmed-meshheading:165185-Receptors, Cell Surface, pubmed-meshheading:165185-Skin, pubmed-meshheading:165185-Thymidine, pubmed-meshheading:165185-Vasopressins
pubmed:year
1975
pubmed:articleTitle
Insulin and epidermal growth factor. Human fibroblast receptors related to deoxyribonucleic acid synthesis and amino acid uptake.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.