1. Detection of antibodies against both isoforms of glutamate decarboxylase in BB/OK rats by western blotting and immuno trapping enzyme activity assay
- Author
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F, Lühder, K P, Woltanski, J, Hamann, I, Klöting, B, Ziegler, and M, Ziegler
- Subjects
Blood Glucose ,Male ,Glutamate Decarboxylase ,Blotting, Western ,Autoantigens ,Rats ,Immunoenzyme Techniques ,Isoenzymes ,Diabetes Mellitus, Type 1 ,Reference Values ,Animals ,Humans ,Electrophoresis, Polyacrylamide Gel ,Female ,Rats, Inbred BB ,Autoantibodies - Abstract
The GABA-producing enzyme glutamate decarboxylase (GAD) is a prominent autoantigen in insulin-dependent diabetes mellitus (IDDM). Autoantibodies against GAD were found with a high prevalence in IDDM patients and in animal models for IDDM. The aim of this study was to detect autoantibodies against both isoforms of GAD in diabetic and non-diabetic but diabetes-prone BB/OK rats by Western blotting and to test their specificity to GAD by an immuno-trapping enzyme activity assay. Eighteen diabetic and 18 non-diabetic BB/OK rats (age 121 +/- 20 days) were investigated. In 10/18 (56%) of the diabetic and 13/18 (72%) of the non-diabetic BB/OK rats autoantibodies against at least one GAD-isoform were detected by Western blotting. In the immunotrapping enzyme activity assay, the mean value of the diabetic (1151 +/- 552 cpm, n = 11) and nondiabetic BB/OK rats (1978 +/- 1213 cpm, n = 10) was significantly (p0.01) increased compared to the LEW. 1A control rats (581 +/- 274 cpm, n = 12). 7/10 (70%) individual sera of the non-diabetic and 5/11 (45%) of the diabetic BB/OK rats were positive in this test. In conclusion, the prevalence of GAD autoantibodies in BB/OK rat is connected with the genetic susceptibility to IDDM but is not a predictor for the onset of the disease in BB/OK rats.
- Published
- 1992