Linked Life Data

165982

Source:http://linkedlifedata.com/resource/pubmed/id/165982

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1975-9-4
pubmed:abstractText
Insulin action is discussed with emphasis on events that occur at the plasma membrane. A summary is presented of previous studies which indicate that the insulin receptor of fat and liver cells is a large glycoprotein, partially buried in the outer surface of the plasma membrane, with a high (K-D approximately 10-10 M) and specific affinity for insulin. The participation of membrane phospholipids in the binding of insulin and the role of sialic acid residues in the transmission of the insulin binding signal are discussed. The relation of insulin action to its effects on cyclic nucleotide levels is explored. On the one hand, insulin action (glucose transport) is inhibited by compounds (cholera toxin, ACTH, glucagon and L-norepinephrine) that stimulate adenylate cyclase; conversely, insulin both inhibits the lipolytic action of these compounds, and raises cellular levels of cyclic GMP. An hypothesis is presented whereby a single cyclase species may be responsible for the formation of either cyclic AMP or cyclic GMP, depending on the nature of the hormone stimulus. The role of membrane phosphorylation in the action of insulin is discussed in the context of experiments demonstrating a specific inhibition by ATP of insulin-mediated glucose transport, in association with the phosphorylation of two specific membrane proteins. The ability of insulin to modulate cyclic nucleotide levels in cultured cells and to act as a growth factor is discussed. Insulin stimulates DNA synthesis and the uptake of alpha-aminoisobutyric acid in human fibroblasts, which effects are also mediated by epidermal growth factor. Insulin acts at concentrations much higher than those obtained in vivo, whereas epidermal growth factor acts at concentrations thought to be physiological. The insulin binding sites (K-D is approximately equal to 10-9 M) related to growth, and observed both in human fibroblasts and in lectin-stimulated and leukemic human lymphocytes would not be appreciably occupied at physiological insulin concentrations. The implications of such 'low affinity' binding sites for insulin are discussed in relation to the action of other growth factors.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0014-9446
pubmed:author
pubmed:issnType
Print
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1556-63
pubmed:dateRevised
2011-11-17
pubmed:meshHeading
pubmed-meshheading:165982-Adipose Tissue, pubmed-meshheading:165982-Adrenocorticotropic Hormone, pubmed-meshheading:165982-Animals, pubmed-meshheading:165982-Atropine, pubmed-meshheading:165982-Cell Division, pubmed-meshheading:165982-Cell Membrane, pubmed-meshheading:165982-Cholera, pubmed-meshheading:165982-Cyclic AMP, pubmed-meshheading:165982-Cyclic GMP, pubmed-meshheading:165982-Female, pubmed-meshheading:165982-Fibroblasts, pubmed-meshheading:165982-Glucagon, pubmed-meshheading:165982-Humans, pubmed-meshheading:165982-Infant, Newborn, pubmed-meshheading:165982-Insulin, pubmed-meshheading:165982-Liver, pubmed-meshheading:165982-Lymphocytes, pubmed-meshheading:165982-Male, pubmed-meshheading:165982-Norepinephrine, pubmed-meshheading:165982-Rats, pubmed-meshheading:165982-Receptors, Cell Surface, pubmed-meshheading:165982-Toxins, Biological
pubmed:year
1975
pubmed:articleTitle
Insulin: interaction with membrane receprots and relationship to cyclic purine nucleotides and cell growth.
pubmed:publicationType
Journal Article