Detection of antibodies against both isoforms of glutamate decarboxylase in BB/OK rats by western blotting and immuno trapping enzyme activity assay.
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 (p < 0.01) 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.
Lühder
F
F
Department of Immunochemistry, Medical Faculty, University of Greifswald, FRG.
Woltanski
K P
KP
Hamann
J
J
Klöting
I
I
Ziegler
B
B
Ziegler
M
M
D000818:Animals; D001323:Autoantibodies / Q000097:blood* / Q000302:isolation & purification; D001324:Autoantigens / Q000276:immunology*; D001786:Blood Glucose / Q000032:analysis; D015153:Blotting, Western; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000276:immunology*; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D005968:Glutamate Decarboxylase / Q000276:immunology*; D006801:Humans; D007124:Immunoenzyme Techniques; D007527:Isoenzymes / Q000276:immunology*; D008297:Male; D051381:Rats; D011913:Rats, Inbred BB; D012016:Reference Values
D001323:Autoantibodies; D001324:Autoantigens; D001786:Blood Glucose; D007527:Isoenzymes; D005968:Glutamate Decarboxylase