ABSTRACT
Objective To demonstrate the carbonic anhydrase Ⅲ (CAⅢ) for 25 000 protein decreased in skeletal muscle of myasthenia gravis (MG). Methods The protein molecular properties responsible to antibodies against 25 000 protein and CAⅢ were analyzed by a combination method of two-dimensional electrophoresis and immuno-Western blot. Competitive binding reactions of the antibodies to the purified 25 000 protein and muscular homogenate were observed by using immuno-Dot blot and immuno-Western blot, respectively. The expression of CAⅢ from normal and MG muscles was detected by immuno-Western blot. Results Combination analysis of two-dimensional electrophoresis and immuno-Western blot showed that the protein of immunological responsible to antibodies against 25 000 protein and CAⅢ had an identical molecular mass and isoelectric point. Competitive binding reactions proved that 25 000 protein and CAⅢ were the same substance, either by immuno-Dot blot or by immuno-Western blot. In addition, a much similar result was obtained when the levels of 25 000 protein from normal and MG muscles were detected by antibodies against 25 000 protein and (CAⅢ) by immuno-Western blot. Conclusion 25 000 protein decreased in the MG skeletal muscle was proved to be just a known protein CAⅢ, which made a basis for further exploring the relationship of CAⅢ deficiency and MG pathogenesis.
ABSTRACT
Objective To investigate the role of ?7nAChR in the pathogenesis of Alzheimer's disease(AD)through exploring the relationship between ?7nAChR and A?_(1-42) in AD brains.Methods The accumulation of ?7nAChR and the possible relationship between ?7nAChR and A?_(1-42) were observed in 3 clinically and pathologically confirmed AD brains by immunohistochemistry. 3 normal brains were set as controls.Results Respective staining of anti-?7nAChR and anti-A?_(1-42) showed that the abnormal accumulation of ?7nAChR existed in AD brains. The main location was at hippocampus and temporal cortex which was just in accordance with senile plaque consisted mainly of A?_(1-42). The major part of ?7nAChR was located extra-cellular and within senile plaque from the view of morphology. No accumulation of ?7nAChR existed in normal brains. Co-staining of anti-?7nAChR and anti-A?_(1-42) further showed that ?7nAChR and A?_(1-42) could accumulate together in senile plaque of AD brain. The average rate of positive co-staining in hippocampus, temporal lobe and frontal lobe is 57.8%, 51.0% and 21.8% respectively. The accumulation of ?7nAChR in hippocampus and temporal lobe seems much than that in the frontal lobe. Conclusion ?7nAChR may combine with A?_(1-42) in AD brains. It is suggested that the combination should destroy the ?7nAChR receptor, block the receptor or mediate the injury of cholinergic neurons with the result of recognition and memory impairment and that ?7nAChR might play an important role in the pathogenesis of Alzheimer's disease.