ISSN:
1432-0428
Keywords:
Insulin receptor
;
phosphotyrosine phosphatases
;
insulin resistance
;
skeletal muscle
;
Zucker rats
;
metformin
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary In order to measure the phosphotyrosine phosphatase (PTPase) activity in small muscle biopsies, a sandwich-immunofluorescence assay was developed using the phosphorylated human insulin receptor as a substrate, a C-terminal insulin receptor antibody as catching antibody and Europium-labelled anti-phosphotyrosine as detecting antibody. Soluble and particulate muscle fractions were prepared from soleus muscle of obese, diabetic (fa/fa) Zucker rats and their lean littermates (Fa/-). In the soluble muscle fractions of the obese (fa/fa) rats PTPase activity was significantly reduced compared to control (Fa/-) rats (45.2±2.6% vs 61.3±4.7%, p〈0.02). This reduction was completely prevented by 24 days of metformin treatment which decreased plasma glucose and plasma insulin levels. In particulate muscle fractions, however, no difference in PTPase activity was found among any groups of rats examined. These results show that the alterations in soluble PTPase activity in the insulin-resistant, diabetic Zucker rat vary with the abnormality in glucose homeostasis.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00403956
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