Effect of altitude hypoxia on glutamate,aspartate and NOS in the rat hypothalamus

AIM: To investigate the effects of external counterpulsation (ECP) on nitric oxide (NO) and nitric oxide synthase (NOS) and the expression of NOS gene in myocardial infarction canines. METHODS: Nineteen healthy dogs were randomly divided into three groups ie. controls, ischemia group, ischemia and ECP group. Serum NO concentrations and myocardium NO levels and NOS specific activity were determined by modified nitrate reductase method. The protein synthesis of sub-type NOS including inducible NOS (iNOS) and endothelial NOS (eNOS) of myocardial tissue were also determined by immunohistochemical method. The constitutive NOS (cNOS) mRNA was measured via in situ hybridization. RESULTS: 120 and 180 minutes after the ligating of LAD, serum NO concentration in ECP groups were higher than those in ischemic groups (P＜0.05). The NO levels and NOS specific activity in myocardium of ischemic dogs were lower than those in controls and ECP group (P＜0.05). Protein synthesis of iNOS increased and that of eNOS decreased in ischemic myocardium. But ECP could control the protein synthesis of iNOS, and increase that of eNOS. Further studies showed that the expression of cNOS mRNA decreased in ischemic myocardial tissue, ECP might promote the expression of it and regulate NOS in the gene level. CONCLUSION: The results suggested that it was one of the most important mechanisms through raising the NO levels to protect ischemic myocardium in ECP.     

蛋鸡和肉鸡下丘脑中生长抑素神经原分布的比较研究

应用免疫组织化学技术显示蛋鸡和肉鸡生长发育过程中下丘脑生长抑素（SS）免疫阳性神经原的分布。研究结果表明两种鸡下丘脑中SS神经原的分布相似，均分布在下丘脑外侧和腹内侧核。下丘脑外侧和腹内侧核的SS神经原可分为两群：中间群和外侧群。通过计数中间群中SS神经原数量发现两种鸡SS神经原数量在生长发育中变化不同。肉鸡在第3周时SS神经原数量最多，于第6周显著减少（P＜0.01)，然后一直维持到第9周。蛋鸡SS神经原数量在第3周时稍增加后于第6周暂时降低（P＜0.05)，然后在第9周时明显增加（P＜0.05)。在发育过程中，肉鸡SS神经原数量的变化比蛋鸡大。尽管肉鸡和蛋鸡SS神经原数量没有明显的性别变化，但公鸡SS神经原的总数比母鸡要高。本实验结果表明蛋鸡和肉鸡下丘脑中SS神经原数量与血浆中GH水平呈负相关，下丘脑中SS神经原数量可以解释蛋鸡和肉鸡血浆中GH水平的差异。     

催产素样免疫反应神经元在鸡下丘脑的分布──ABC法研究

ＡＢＣ法研究结果表明，催产素（ＯＴ）样神经元在鸡下丘脑中分布于一条前端尖细、中央宽厚、后端钝圆的长梭形细胞带内，带的前端达前联合核、皮质联合床核，后端达乳头体各核团，中央部分包括视上核、室旁核、视交叉上核、腹内侧核、腹外侧核、背内侧核、背外侧核、弓状核、室周核等，ＯＴ样神经纤维主要分布在第三脑室室周和正中隆起的中间带和外侧带。通过ＯＴ释放途径的观察，对ＯＴ在体内的含量变化进行了讨论     

猪脑内微量注射大豆黄酮对血浆LH水平的影响

 在去势格丁根小公猪 (n =9)下丘脑MBH和VM部位注射大豆黄酮 (10 μl/头 ,8pg/ μl) ,注射后血浆LH浓度变化呈上升趋势 :在MBH部位 ,注射后 0 .5～ 2h有 4例 (4/ 5 )LH水平较注射前升高 ,1例 (1/ 5 )变化不明显 (P≤0 .0 5 ) ,注射 2 .5h后与注射前比较无明显变化 ;在VM部位 ,注射后 3例 (3/ 4 )升高 ,1例变化不明显。对照组除 1例外 ,其他在处理前后LH水平的变化不明显。结果说明 ,大豆黄酮可在下丘脑水平上增加去势公猪LH的分泌     

仔猪下丘脑内生长抑素mRNA的分布定位——原位杂交组织化学法研究

用原位杂交组织化学法研究了５只仔猪下丘脑内生长抑素ｍＲＮＡ的分布。结果表明，生长抑素ｚｎＲＮＡ主要见于下丘脑腹内侧核、穹窿周核、腹外侧核、弓状核、室旁核和室周核，此外在视交叉上核、视上核、下丘脑前区和后区偶见零散标记细胞。本研究结果与在绵羊和豪猪上用免疫组织化学法获得的结果略有不同，除与研究方法和种属差异有关外，还可能与实验动物年龄有关。     

GnRH神经元在发情期奶山羊下丘脑中的免疫组化定位

为了研究促性腺激素释放激素(GnRH)在发情期奶山羊下丘脑中的表达特点,采用超敏的免疫组化链霉素抗生物素蛋白-过氧化物酶法研究GnRH免疫反应神经元在发情期山羊下丘脑中的分布。结果显示,GnRH免疫反应阳性细胞主要分布在视上核、视前内侧核、视前外侧核、交叉上核、丘脑外侧区、室旁核后部、弓状核、腹外侧核、结节乳头体核、乳头体内侧核、乳头体外侧核等核团。阳性细胞的形态有圆形、三角形、卵圆形、梭形、多角形、不规则形,有些阳性细胞还具有明显的突起。圆形和三角形细胞直径的大小为5~35μm,卵圆形和梭形细胞短轴和长轴大小分别为5~27μm、15~58μm。免疫反应阳性产物还分布于部分纤维束中,如视束、正中中隆起等。根据细胞中阳性反应的强弱可分为强阳性,如交叉上核;中等阳性,如乳头体内侧核;弱阳性,如前穹窿周核。上述研究结果表明,GnRH在成年奶山羊下丘脑广泛存在。     

初情期启动过程中小尾寒羊下丘脑GnRH基因甲基化状态及表达量关系研究

初情期启动的早晚关系到雌性动物的繁殖性能,GnRH是动物初情期启动过程中的关键基因,其启动子区甲基化状态与GnRH mRNA表达量之间的关系尚不清楚。本研究选择初情期前、临近初情期和初情期雌性小尾寒羊的下丘脑作为样本,利用亚硫酸氢盐测序(BSP)技术和实时荧光定量PCR(qRT-PCR)技术检测了初情期不同阶段小尾寒羊GnRH启动子区的甲基化状态和GnRH mRNA的表达量,并分析二者之间的关系。结果表明:小尾寒羊到达初情期时,GnRH基因启动子区甲基化水平显著降低(P0.05),尤其是在启动子区-570位点降低最明显,而随着初情期的启动GnRH mRNA表达量呈上升趋势。结果提示,初情期启动过程中,GnRH mRNA表达量升高可能与下丘脑GnRH基因启动子区特定位点甲基化水平降低存在一定的关系。     

TNF-α对下丘脑神经元的影响研究进展

介绍了肿瘤坏死因子TNF-α的发现、结构及其作用的信号通路,并从神经元的发育、生存、离子平衡和神经递质释放等方面综述了近年来TNF-α对下丘脑的影响研究进展.     

Chicken folliculo-stellate cells express thyrotropin receptor mRNA

We investigated the presence of thyrotropin receptor (TSHR) mRNA in chicken pituitary and brain, and quantified the changes in its expression during the last week of embryonic development. We found that in the pituitary gland, TSHR mRNA co-localizes with folliculo-stellate cells but not with thyrotropic cells, suggesting the existence of a paracrine ultra-short thyrotropin feedback loop. TSHR mRNA was also present throughout the diencephalon and various other brain regions, which implies a more general function for thyrotropin in the avian brain. During late embryogenesis, when the activity of the hypothalamo-pituitary-thyroidal axis increases markedly, a significant rise in TSHR mRNA expression was observed in pituitary, which may signify an important change in pituitary ultra-short thyrotropin feedback regulation around the period of hatching.