【摘要】 目的:观察高碘对小鼠室旁核一氧化氮合酶阳性神经元的变化,探讨高碘对中枢神经系统的影响。方法:实验于2004-01/2004-10在河北医科大学完成。选择昆明种初断乳健康小鼠16只,随机分为适碘组与高碘组,每组8只。分别以含碘量为50μg/L,3000μg/L蒸馏水喂养小鼠6个月,于实验第180天断颈处死动物,摘取甲状腺,制作病理切片,苏木精-伊红染色,光镜下观察甲状腺的形态变化证实高碘甲状腺肿模型复制成功。采用还原型尼克酰胺腺嘌呤二核苷酸脱氢酶组织化学方法观察高碘对小鼠下丘脑室旁核一氧化氮合酶阳性神经元的影响。结果:在实验过程中各组动物无异常死亡,均进入结果分析。①光镜下可见适碘组甲状腺滤泡大小形态不一,滤泡腔内有中等量的粉红色胶质,滤泡为单层立方状或高柱状,核圆形或椭圆形位于细胞中央,细胞质中等,毛细血管丰富;还原型尼克酰胺腺嘌呤二核苷酸脱氢酶阳性神经元呈高尔基样分布于室旁核外围,细胞形态为多角形、梭形、椭圆形,胞浆饱满且呈兰色深染,突起明显,有较多深染的纤维。②光镜下高碘组甲状腺滤泡明显扩张,腔内充满大量染色的红色胶质滤泡上皮细胞、扁平,核呈梭形,滤泡间质减少;室旁核仅见零星散在的还原型尼克酰胺腺嘌呤二核苷酸脱氢酶阳性神经元,细胞形态以梭形、椭圆形为主,胞浆淡染,胞核不染色,突起不明显,几乎见不到阳性纤维。③高碘组室旁核一氧化氮合酶阳性细胞密度较适碘组明显降低,差异有显著性[(24±2.7),(81.5±3.5)个/0.01mm2,t=2.306～3.355,P<0.01)。结论:高碘可以引起小鼠室旁核细胞一氧化氮合酶染色阳性神经元密度明显降低且染色变浅,突起变短。高碘可能通过引起小鼠下丘脑室旁核细胞一氧化氮合酶阳性细胞的变化而影响一氧化氮合成,从而可能对中枢神经系统功能造成影响。更多还原

【Abstract】 AIM: To observe the effect of high iodine on nitric oxide synthase (NOS) positive neurons in paraventricular nucleus (PVN)of mice and explore the effect of high iodine on central nervous system. METHODS: The experiment was conducted in Hebei Medical University from January to October 2004. Sixteen weaning Kunming mice were randomly divided into proper iodine group and high iodine group with 8 mice in each group. Mice in the two groups were fed with distilled water containing iodine 50 μg/L and 3 000 μg/L respectively for six months. At the 180th day of experiment, mice were killed by cutting off heads, thyroid glands were made into pathological section, so as to be observed under hematoxylin-eosin staining. light microscope Thyroid gland were obtained and the morphologic changes was observed under the reconstruction of goiter model succeeded. Nicotinamide adenosine dinucleotide phosphate diaphorase (NADPH-d) histochemical method was used to oserve the effect of high iodine on NOS positive neurons in hypothalamic PVN ofmice. RESULTS: No subject died abnormally in the experiment, all of them were involved in the analysis of results.①Under microscope, size and shape of thyroid follicles in the control group were different, and there were moderate pink colloid in the follicular cavities, the follicles were cubic or cylinder and in the center of cells they were round or oval with moderate cytoplasm, but blood capillaries were plentiful; The deoxidized NADPH-d positive neurons distribution were Golgi-like around PVN, and the cellular shapes were polygon, fusiform, oval, the endochylema was full with blue deep stained and distinct ecphyma, and there were much stained fibers.②Thyroid follicles in the high-iodine group under light microscope dilated obviously, and there were abundant applanatus stained pink colloid follicular epithelial cells inside the cavity, which were in fusiform shape with follicular stroma decreased; Only sporadic NADPH-d positive neurons could be seen in PVN, and they were mainly in fusiform and oval shape with light stained cytoplasm and no-stained nucleus, the ecphyma was not significant, few positive fibers could be seen.③The positive cell dencity of NOS in the PVN of high-iodine group was lower than that in the proper iodine group, and the differences were significant (24±2.7),(81.5±3.5)/0.01 mm2,t=2.306-3.355,P < 0.01 .CONCLUSION: High iodine can cause the density of NOS stained positive neurons in PVN of mice decreased obviously with lighter stain and shorter ecphyma. High iodine can also affect the synthesis of NOS by influencing the changes of NOS positive cells in hypothalamus PVN of mice, thus affect the central neurological function.更多还原