| Huntington’s disease(HD) was a human autosomal dominant genetic disease, patients with involuntary dance-like movements and progressive cognitive disorder, eventually leading to dementia and even death, the disease was widely distributed throughout the world, in Europe and America affected as much. Nitric oxide(NO) was a messenger molecule that mediates a variety of physiological functions, which catalyzed nitric oxide synthase(NOS),and was produced by the oxidation L- arginine: O2+L-Arg?? ??NOSNO+Citrulline.This test selected three-month-old rabbits were 60, weight(2 300±200) g, were randomly divided into normal control group, model group, L-NNA treatment group and tiapride treatment group, every groups of 15. Using the stereotaxic technology in the right striatum injected 6μL quinoline acid to made HD model Rabbits, and then used the NOS inhibitor Nω-nitro-L- arginine(L-NNA) and tiapride compare treatment.Used behavioral and immunohistochemical methods to detect the HD model. Behavioral tests showed that the right rotation, tumbling and other acute excitotoxic behavior occurs within 24 hours after surgery. HE sections could be seen in neuronal loss and gliosis,immunohistochemistry test results showed that the frontal lobes and the striatum was rich in the shape of a circular or oval calcium-binding protein immunoreactive neurons, the size was medium, cell body was clean cut, deeply stained, immunoreactivity mainly concentrated in the perinuclear cytoplasm; the frontal and striatal in model group decreased significantly compared to the number of calcium-binding in the control group and the cell body contours blurred.By nitrate reductase and biochemical methods to detect the serum and brain tissue of NO content and NOS activity, immunohistochemistry to observed the expression of various brain tissue NOS positive neurons, and explore effect on NO content, NOS activity and NOS positive neurons morphology about NOS inhibitor L-NNA.. NOS activity assay showed that:each group total nitric oxide synthase(TNOS) and inducible nitric oxide synthase(i NOS) in the model with the highest content, to 35 days when returned to normal levels; in the striatum,the early L-NNA group reduced NOS activity better than tiapride group(P <0.01). NO content test results showed: NO content was the highest concentrations in the model group,each group of frontal lobe, hippocampus and striatum of NO content was consistent with the NOS activity in homogenates. By SABC immunohistochemical staining under a microscope observed the morphology and distribution in frontal, hippocampus and striatum of neuronal nitric oxide synthase(nNOS) and iNOS positive neurons in each group. The results showed:the model group nNOS positive neurons density significantly reduced compared with the normal group, the cell body cross-sectional area decreases, positive neurons poorly defined,reducing the number of projections; and iNOS positive neuronal density was significantly increased compared to normal group, cytoplasmic staining deepen, clean cut, significantly increased the number of first-class projection and cross-sectional area of the cell body.Indicators iNOS positive neurons L-NNA group than tiapride group was lower.The results showed that HD model group by site-directed injection of quinolinic acid making part of the striatum neuronal loss associated with the death of neurons and iNOS expression was enhanced, increasing NO content, high concentrations of NO exert neurotoxic effects, suggesting that NO was involved in the pathogenesis of HD models, increasing the extent of brain tissue damage. NOS inhibitor L-NNA by inhibiting NOS activity, decreased brain tissue NO content of HD neurons play a protective role. Given the similarity of the rabbit model with HD patient brain lesions, suggesting that L-NNA and tiapride could be used for the treatment of Huntington’s disease, but there ware time, does, incompatibility and duration of medication need to further study. |
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