Linked Life Data

8419148

Source:http://linkedlifedata.com/resource/pubmed/id/8419148

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-2-5
pubmed:abstractText
Membrane-associated tyrosine phosphatase activities were studied in two distinct states of insulin resistance: diabetes and pregnancy. Using a novel immunoenzymatic assay with intact insulin-like growth factor-I (IGF-I) and insulin receptors as substrates, we show that phosphotyrosine-protein phosphatases (PTP-ases) from normal rat tissues induce a decrease in tyrosine phosphorylation of both receptors. Membrane fractions from kidney, brain, and liver contain the highest PTP-ase activity toward the insulin receptor. After 20-day streptozotocin-induced diabetes, PTP-ase activities are increased by 70% in the placenta, reduced by 40-50% in liver and skeletal muscle, and remained unchanged in the nonclassical insulin target tissues, kidney and brain. In general, the dephosphorylation of IGF-I receptor follows a pattern similar to that of insulin receptor except in red skeletal muscle in which it is not modified. Pregnancy also induces alterations of liver PTP-ases similar to those elicited by diabetes with a 50% reduction of insulin and IGF-I receptor dephosphorylation. This effect of pregnancy is further potentiated by diabetes. The alterations in the activity of hepatic PTP-ases from diabetic and pregnant rats are associated with a decreased autophosphorylation of the insulin receptor, suggesting that the diminution of phosphatase activity might be associated to the state of receptor phosphorylation and activation. Our data demonstrate that alterations of PTP-ases in insulin target tissues are found in two insulin-resistant states, one characterized by hyperinsulinemia, pregnancy and one by insulinopenia, streptozotocin-diabetes. These observations suggest a possible relationship between the defective activity of receptor tyrosine kinases and membrane-associated phosphatases from insulin responsive tissues.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
132
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
67-74
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Alteration of phosphotyrosine phosphatase activity in tissues from diabetic and pregnant rats.
pubmed:affiliation
Inserm U. 145, Faculté de Médecine, Nice, France.
pubmed:publicationType
Journal Article