Relationship of insulin binding and insulin-stimulated tyrosine kinase activity is altered in type II diabetes.
AUTOR(ES)
Comi, R J
RESUMO
The insulin receptor contains an alpha subunit with insulin binding properties and a beta subunit with insulin-stimulated tyrosine kinase function. Preparations containing insulin and insulinlike growth factor I (IGF-I) receptors were obtained from solubilized human red cell membranes by affinity chromatography. After separate assays for insulin binding and insulin-stimulated tyrosine kinase activities, a high degree of correlation was found between these activities in preparations from normals and diabetics. Identical studies using IGF-I as the ligand showed a lesser degree of correlation. We compared 24 normal subjects and 14 untreated type II diabetics and found significant diminution in the slope of the line coupling insulin binding and insulin-stimulated kinase activities in the diabetics. This difference was not observed in a similar study of IGF-I-related activities. Compared to normal controls, untreated type II diabetics have reduced tyrosine kinase activity stimulated per unit insulin binding.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=424100Documentos Relacionados
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