The Experimental Investigation Of Chronic Parkinson's Desease Of Mouse Model Induded By MPTP

Objective⒈To observe decrease and apoptosis of dopaminergic neurons in mouse model of parkinsonism induced by little dose of 1-methyl-4-phenyl-1,2,3,6– tetrahydropyridine (MPTP) injection.⒉To observe expression ofα-synuclein in chronic mouse model of parkinsonism induced by little dose of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine(MPTP) injection. MethodsThis investigation adopted mouse(C57BL) model of chronic parkinsonism induced by little dose of MPTP injection, set test group and control group, the test group received bake hypodermic injections of MPTP, the control group received bake hypodermic injections of physiology saline, after treatment to every group, observed at different periods of time if there were parkinsonism symptom on mice, observed loss phenomenon of substantia nigra neurons morphologically with HE staining, and detected expression of tyrosine hydroxylase(TH) andα-synuclein with SP immunohistochemistry, detected apoptosis of dopaminergic with TUNEL.Results⒈Behavior observation results: compared with the control group, the pole climbing time of test group was obviously lasting(p<0.05), and those treated with MPTP displayed markedly hypoactive behavior, the control group didn't display parkinsonism behavior.⒉Morphologic examination results: after HE dyeing, compared with the control group, the loss of dopaminergic neurons of the test group decreased obviously.⒊SP immunohistochemistry results: the first day, third week, second month, sixth month after the treatment, the count of TH positive of the test group decreased obviously, CPC werel markedly different with the control group(p<0.05). The TH expression of test group changed in different period of time after treatment, TH positive staining decreased on the first day after injections, reached the peak, then rised again gradually at the third week, positive staining of the test were still less than that of the control group as far as the sixth month.⒋TUNEL results: the first day, third week, second month, sixth month after the treatment, the test group displayed many brown stained apoptosis cells, these cells centralized mainly in substantial nigra, the control group displayed no apoptosis. ⒌SP immunohistochemistry results ofα-synuclein: on the first day, third week, second month, sixth month after the treatment, compared with the control group, masculine dyeing ofα-synuclein of the test group increased, the number of masculine cells increased, displayed marked difference(p<0.05), masculine expression ofα-synuclein of the test group increased in different phase after treatment, it appeared on the first day after treatment, reached the peak at the third week, then decreased gradually, but still more than the first day and expressed continuously till the sixth month.Conclusion⒈MPTP induced C57BL mouse to appear parkinsonism symptom, C57/BL mouse displayed decrease and apoptosis of dopaminergic neurons in substantial nigra, and the process of the disease was chronic.The test prompted that apoptosis attended in mechanisms of PD in MPTP chronic parkinsonism model. MPTP chronic parkinsonism model was more able to represent natural couse of Parkinson's disease.⒉MPTP long-term injected can induced substantial nigraα-synuclein in chronic mouse model of parkinsonism to increase continuously and accumulate abnormally untill the sixth month.