Related Experiment Videos
Low molecular weight GTP-binding proteins are altered in platelet hyperaggregation in IDDM
1Department of Internal Medicine, University of Texas Medical Branch, Galveston 77555-1060.
Oncogene
|February 1, 1993
Summary
Patients with insulin dependent diabetes mellitus (IDDM) show hyperaggregating platelets with altered distribution of guanine nucleotide-binding proteins. These changes in GTP-binding proteins may regulate platelet hyperactivity in diabetes.
Area of Science:
- Biochemistry
- Cell Biology
- Endocrinology
Background:
- Insulin dependent diabetes mellitus (IDDM) is associated with increased platelet aggregation.
- The role of guanine nucleotide (GTP)-binding proteins in platelet function in IDDM is not fully understood.
Purpose of the Study:
- To investigate the hypothesis that hyperaggregating platelets in IDDM have altered location and function of GTP-binding proteins.
- To identify specific GTP-binding proteins affected in IDDM platelets.
Main Methods:
- Collected and washed platelets from 10 IDDM patients and 12 healthy controls.
- Assessed thrombin-induced platelet aggregation.
- Identified and quantified GTP-binding proteins using [32P]-GTP binding assays and SDS-PAGE.
Main Results:
- IDDM platelets exhibited significantly increased aggregation in response to thrombin.
- A decrease in 27/28 kDa GTP-binding proteins in platelet membranes and an increase in the cytosol of IDDM platelets.
- A reduction in the 21 kDa GTP-binding protein in the platelet membrane of individuals with IDDM.
Conclusions:
- Increased platelet aggregation in IDDM is linked to altered cellular distribution of 27/28 kDa GTP-binding proteins.
- Low molecular weight GTP-binding proteins, particularly in the 27/28 kDa range, may play a key regulatory role in platelet hyperaggregation in diabetes.