长短日照下绍鸭性成熟时间,下丘脑GnRH-Ⅰ、POMC和NPY mRNA表达的差异

利用长日照和短日照环境调控绍鸭的性成熟时间,并采用反转录多聚酶链式反应（RT．PCR）方法,检测两种日照组（n=6）鸭性成熟过程中下丘脑促性腺激素释放激素-Ⅰ（GnRH-Ⅰ）、阿片促黑激素皮质素原（POMC）和神经肽Y（NPY） mRNA表达的发育性变化及日龄间差异。结果表明,长日照组性成熟时间较短日照组提前30d。RT-PCR结果显示,两组鸭下丘脑GnRH-Ⅰ mRNA的发育性表达模式相似,从出雏至性成熟过程中,其表达水平呈逐渐增加趋势;长日照组下丘脑GnRH．ImRNA表达丰度均高于同日龄短日照组,并于120日龄时其差异达显著水平。两组POMC mRNA的表达丰度呈现先增加后降低趋势,于性成熟前后显著下降;日照长度对其基因表达具有显著影响。两组NPYmRNA表达水平分别于60和90日龄时显著升高,于性成熟时显著下降,但光照对其基因表达无显著影响。下丘脑GnRH-Ⅰ基因表达的显著上调可能是禽类性成熟启动的关键因素,也是长日照条件下绍鸭性早熟的主要原因;GnRH-Ⅰ表达的上调与下丘脑POMC和NPY mRNA表达变化有关。     

NPY和POMC基因在生长差异与饥饿再摄食鳙个体中的表达分析

为研究摄食促进基因和摄食抑制基因对鱼类生长调控和饥饿再摄食过程的影响,研究克隆了鳙神经肽Y(HynNPY)基因和前阿黑皮素原(HynPOMC)基因cDNA序列,采用qRT-PCR技术分析它们在生长显著差异鳙个体下丘脑、肠中的基因表达变化;设置对照组(连续投喂4周)、饥饿组、饥饿再摄食组,分析NPY和POMC在不同处理组鳙的下丘脑、肠中的基因表达变化。鳙NPY和POMC基因cDNA全长分别为839和799 bp,开放阅读框有291和657 bp,分别编码96和218个氨基酸。系统进化分析结果表明,鳙NPY和POCM基因具有高度保守性。鳙NPY在下丘脑的表达量最高,其次为肠和脑; POMC在肠道中的表达量最高,其次为下丘脑和肝脏。在相同环境下生长差异鳙个体的下丘脑和肠中, NPY在极大个体的表达量高于极小组个体, POMC在极小个体中的表达量高于极大个体。饥饿导致NPY在下丘脑表达上升,在肠表达量显著上升,恢复摄食后, NPY在下丘脑和肠中表达量下降; POMC在饥饿组下丘脑和肠中都表现为表达量呈显著上升,复投喂后POMC表达量逐步下降至接近对照组水平。肠组织学观察显示,极大个体的肠腔直径...     

限食条件下下丘脑神经肽基因表达量对中缅树鼩体质量调节的影响

为阐明中缅树鼩Tupaia belangeri下丘脑神经肽基因表达量在限食条件下的体质量调节作用,本研究测定了限食(正常摄食量的80%)条件下中缅树鼩的体质量、体脂含量、血清瘦素浓度以及神经肽Y(NPY)、刺鼠相关蛋白(AgRP)、阿片促黑色素原(POMC)和可卡因-安他非明转录调节肽(CART)表达量。结果表明:限食极显著降低中缅树鼩的体质量和体脂含量(P0.01)。对照组和限食组的血清瘦素浓度差异有统计学意义(P0.05),血清瘦素浓度与体脂含量呈正相关。下丘脑神经肽基因NPY、AgRP、POMC和CART表达量差异有高度统计学意义(P0.01)。以上结果表明限食可以降低中缅树鼩的体质量、体脂含量和血清瘦素浓度,调整下丘脑神经肽基因表达量。瘦素通过调节NPY/AgRP和POMC/CART表达量来调节中缅树鼩的体质量。     

GnRH及其受体在性成熟前后鲇、黄颡鱼脑、垂体和卵巢中的免疫细胞化学定位

用链霉亲和素 -生物素化过氧化物酶复合物 (StreptAvidinBiotin peroxidaseComplex ,SABC)免疫细胞化学方法 ,使用促性腺激素释放激素 (Gonadotropin releasinghormone ,GnRH)以及促性腺激素释放激素受体 (GnRHR) 2种抗血清对性成熟前后的黄颡鱼 (Pelteobagrusfulvidraco)和鲇鱼 (Silurusasotus)的脑、垂体、卵巢中的免疫活性内分泌细胞进行了免疫细胞化学定位。结果表明GnRH和GnRHR免疫活性在两种鱼的各脑区、垂体、卵巢中均有分布 ;两种鱼在性成熟时它们的下丘脑、垂体和卵巢中的GnRH和GnRHR免疫反应细胞数目和免疫反应强度明显高于性成熟前。本文讨论了GnRH、GnRHR直接或间接参与黄颡鱼和鲇鱼性腺发育成熟调节的可能性及形态学证据。可为下丘脑 垂体 性腺轴、神经 内分泌、GnRH功能的多样性等研究领域提供新的形态学依据。     

大鼠发情期和间情期下丘脑ghrelin mRNA的表达

为探索下丘脑ghrelin mRNA及GnRH mRNA在大鼠(Rattus norregicus)发情期和间情期的表达特点,通过外部观察和阴道涂片相结合的方法确定发情期和间情期,将12只未经产SD雌性大鼠分为2组,即发情期组和间情期组,每组6只。取动物下丘脑,用实时荧光RT-PCR方法检测ghrelin mRNA和GnRH mRNA的表达丰度。结果表明,间情期组大鼠下丘脑ghrelin mRNA的表达丰度显著高于发情期组(P<0.01);间情期组大鼠下丘脑GnRH mRNA的表达丰度显著低于发情期组(P<0.01)。研究发现,下丘脑ghrelin mRNA和GnRH mRNA在发情期与间情期具不同的表达模式,提示ghrelin可能在下丘脑水平上对GnRH mRNA的表达具下调作用。     

大鼠垂体促性腺激素细胞内cAMP的改变对LHβ mRNA表达的影响

目的 分析大鼠LHβ mRNA表达的促性腺激素释放激素(GnRH)受体后信号转导机制.方法 将体外培养的大鼠腺垂体促性腺激素(GTH)细胞用cAMP的兴奋剂FSK或抑制剂SQ22536处理后,再用高频GnRH脉冲刺激,然后用实时荧光定量PCR法测定细胞LHβ mRNA的Ct值,并与空白组比较.结果 LHβ mRNA的Ct值随着GTH细胞cAMP含量的增高而显著降低,随着cAMP含量的降低而显著增高.结论 cAMP是高频GnRH脉冲刺激所引起的LHβ mRNA表达的受体后的信号转导途径.     

大鼠促性腺激素细胞内蛋白激酶C的改变对黄体生成素mRNA表达的影响

目的:分析大鼠黄体生成素(LH)表达的受体后信号转导机制。方法:促性腺激素(GTH)细胞内蛋白激酶C(PKC)兴奋或抑制后,用促性腺激素释放激素(GnRH)脉冲刺激,然后用实时荧光定量PCR方法测定细胞LH的β亚基(LHβ)mRNA的表达量,并与空白组比较。结果:LHβmRNA随着PKC活性的升高而显著升高,随着PKC活性的降低而显著降低。结论:GnRH脉冲刺激引起LHβmRNA表达,其受体后的信号转导是PKC-Ca2+途径。     

光周期对蛋鸡GnRH-I,GnRH-Ra mRNA表达和卵巢发育的影响

60只75日龄ISA褐蛋鸡随机分成长光组(LL)和短光组(SL),试验期70 d。短光组恒定光/暗:8 h/16h;长光组起始光/暗:8 h/16 h,每周增加0.5 h,最长光/暗达到13 h/11 h。分别于105和136日龄每组取6羽蛋鸡采样,观察光周期对蛋鸡GnRH-I mRNA,GnRH-Ra mRNA表达以及卵巢发育的影响。结果表明:136 d长光组GnRH-I mRNA表达的丰度显著高于短光组(P0.05),且极显著高于105 d长光组和短光组的表达(P0.01)。136 d短光组GnRH-Ra mRNA表达较105 d显著下降(P0.05),长光组GnRH-Ra mRNA的表达丰度显著高于短光组(P0.05)。136 d长光组的卵巢重、卵巢指数极显著高于短光组(P0.01)。以上说明,长光明显上调开产前蛋鸡下丘脑GnRH-I mRNA的表达,促进卵巢的发育;短光则明显下调垂体GnRH-Ra mRNA的表达,致使卵巢发育延缓。     

逍遥散对慢性束缚应激模型大鼠相关脑区CRF基因表达的影响

目的:观察慢性束缚应激大鼠相关脑区CRF mRNA(下丘脑、垂体、海马、皮层)含量变化以及逍遥散对其影响.方法:用RT-PCR和图像分析方法测定相关脑区CRF mRNA含量变化.结果:应激组较正常对照组在下丘脑CRF-1基因表达下调(P<0.01).在下丘脑逍遥散组较应激组CRF-1基因表达显著下调(P<0.01),CRF-2基因表达显著上调(P<0.01);在海马区逍遥散组CRF-2基因表达较模型组上调(P<0.05);在皮层逍遥散组CRF-1基因表达较应激组则显著上调(P<0.01).结论:逍遥散组对慢性束缚应激中枢神经肽CRF的调节位点在下丘脑、垂体、海马和皮层,充分证实逍遥散的调节靶点与下丘脑、边缘系统及皮层中枢有关.     

Land,livestock, and livelihoods: Changing dynamics of gender,caste, and ethnicity in a Nepalese Village

Over the past 10 years, Ghusel VDC, Lalitpur District has moved from primarily subsistence agriculture into the wider cash economy aided by the Small Farmers' Development Program (SFDP), which provides credit to farmers mainly for the purchase of buffalo for milk production, and by the National Dairy Corporation, which supports local dairy cooperatives. Analysis reveals that buffalo-keeping and milk sales are increasing the well-being of many households, while at the same time creating new inequalities in gender roles and responsibilities, greater inequities between Brahmin and Tamang residents in Ghusel, and placing pressures on the ecosystem for increased supplies of fodder and fuelwood. Evidence suggests that there is critical, need for attention to the social, and particularly gender-based, implications of maintaining livestock for milk sales and to the ecological underpinnings of this livelihood system.     

Microparticles in physiological and in pathological conditions

Chronic diseases pose a severe burden to modern National Health Systems. Individuals nowadays have a far more extended lifespan than in the past, but healthy living was only scantily extended. As much as longer life is desirable, it is saddened by chronic diseases and organ malfunctions. One contributor to these problems was recognized to be represented by microparticles (MPs). Our purpose is to better understand MPs, to contrast their ominous threat and possible clinical importance. For this intent we correlated MPs with thrombotic pathologies, hemophilia, malaria, diabetes, cardiovascular diseases, endothelial dysfunctions, pulmonary hypertension, ischemic stroke, pre-eclampsia, rheumatologic diseases-rheumatoid arthritis, polymyositis-dermatomyositis, angiogenesis and tumor progression-cancer; we listed the possibilities of using them to improve transfusion methods, as a marker for acute allograft rejection, in stem cell transplantation, as neuronal biomarkers, to understand gender-specific susceptibility for diseases and to improve vaccination methods and we presented some methods for the detection of MPs.     

眶额叶微量注射谷氨酸和γ-氨基丁酸对胃运动的影响及其机制探讨

目的:研究眶额叶(OFC)的谷氨酸(Glu)和γ-氨基丁酸(GABA)含量变化对胃运动的影响及其调节神经机制。方法:实验采用了大鼠眶额叶微量注射给药,结合核团损毁的方法,以记录胃内压,统计胃收缩幅度作为胃运动变化的指标。结果:①OFC注射Glu可显著降低胃收缩幅度,损毁杏仁核后可反转该效应,胃收缩幅度显著增强;损毁蓝斑核后,Glu的作用无显著性变化。②OFC注射GABA可显著增强胃的收缩幅度,损毁蓝斑核后消除该效应;损毁杏仁核后,胃收缩幅度进一步增强。结论:外源性增加OFC区Glu含量导致的抑胃效应可能是通过增强了杏仁核的经常性抑胃作用而引起的;而增加OFC区GABA的含量引起的胃运动增强与蓝斑核密切相关。     

Chromium accumulation, translocation and chemical speciation in vegetable crops

Trivalent chromium (Cr³⁺) is essential for animal and human health, whereas hexavalent Cr (CrO₄ ²⁻) is a potent carcinogen and extremely toxic to animals and humans. Thus, the accumulated Cr in food plants may represent potential health hazards to animals and humans if the element is accumulated in the hexavalent form or in high concentrations. This study was conducted to determine the extent to which various vegetable crops absorb and accumulate Cr³⁺ and CrO₄ ²⁻ into roots and shoots and to ascertain the different chemical forms of Cr in these tissues. Two greenhouse hydroponic experiments were performed using a recirculating-nutrient culture technique that allowed all plants to be equally supplied with Cr at all times. In the first experiment, 1 mg L⁻¹ Cr was supplied to 11 vegetable plant species as Cr³⁺ or CrO₄ ²⁻, and the accumulation of Cr in roots and shoots was compared. The crops tested included cabbage (Brassica oleracea L. var. capitata L.), cauliflower (Brassica oleracea L. var. botrytis L.), celery (Apium graveolens L. var. dulce (Mill.) Pers.), chive (Allium schoenoprasum L.), collard (Brassica oleracea L. var. acephala DC.), garden pea (Pisum sativum L.), kale (Brassica oleracea L. var. acephala DC.), lettuce (Lactuca sativa L.), onion (Allium cepa L.), spinach (Spinacia oleracea L.), and strawberry (Fragaria ×  ananassaDuch.). In the second experiment, X-ray absorption spectroscopy (XAS) analysis on Cr in plant tissues was performed in roots and shoots of various vegetable plants treated with CrO₄ ²⁻ at either 2 mg Cr L⁻¹ for 7 d or 10 mg Cr L⁻¹ for 2, 4 or 7 d. The crops used in this experiment included beet (Beta vulgaris L. var. crassa (Alef.) J. Helm), broccoli (Brassica oleracea L. var. Italica Plenck), cantaloupe (Cucumis melo L. gp. Cantalupensis), cucumber (Cucumis sativus L.), lettuce, radish (Raphanus sativus L.), spinach, tomato (Lycopersicon lycopersicum (L.) Karsten), and turnip (Brassica rapa L. var. rapifera Bailey). The XAS speciation analysis indicates that CrO₄ ²⁻ is converted in the root to Cr³⁺ by all plants tested. Translocation of both Cr forms from roots to shoots was extremely limited and accumulation of Cr by roots was 100-fold higher than that by shoots, regardless of the Cr species supplied. Highest Cr concentrations were detected in members of the Brassicaceae family such as cauliflower, kale, and cabbage. Based on our observations and previous findings by other researchers, a hypothesis for the differential accumulation and identical translocation patterns of the two Cr ions is proposed. Received: 27 February 1998 / Accepted: 2 April 1998     

Existence and Functions of Neurotens in Human Early Placental Villi

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Expression of mRNA for PACAP and its receptors in intra- and extra-adrenal human pheochromocytomas and their relationship to catecholamine synthesis

Purpose: Pituitary adenylate cyclase-activating polypeptide (PACAP), a member of the secretin/glucagons/vasoactive intestinal peptide family, induces the expression of catecholamine-synthesizing enzymes in adrenal medullary cells. In addition, PACAP and its receptor have been detected in human pheochromocytoma tissues, though it is not yet known whether PACAP enhances the expression of genes encoding catecholamine-synthesizing enzymes. To address this question, we analyzed PACAP, PACAP receptor, and tyrosine hydroxylase (TH) and phenylethanolamine-N-methyltransferase (PNMT) mRNAs in pheochromocytomas. Methods: The levels of the mRNA for PACAP and vasoactive intestinal peptide (VIP), and their receptors, and for TH and PNMT were measured by RT-PCR or real-time PCR analysis, and the concentrations of catecholamines were measured by HPLC in 24 intra-adrenal and six extra-adrenal pheochromocytomas. Results: mRNA expression of PACAP and its receptor VPAC1R were detected in many pheochromocytomas (24/30 and 29/30, respectively), but mRNA expression of the PAC1R and VPAC2R receptor subtypes were detected in only one of six extra-adrenal pheochromocytomas. PACAP mRNA expression correlated with TH (p=0.0018) and PNMT (p=0.05) mRNA expression, as well as epinephrine (p=0.0342) levels in 16 intra-adrenal pheochromocytomas. Conclusion: Our findings support a possible role for PACAP in the regulation of expression of genes encoding catecholamine-synthesizing enzymes in intra-adrenal pheochromocytomas.     

SPR生物传感器的特点及其在生物特异性相互作用分析中的应用

利用表面等离子模共振技术（SPR）进行生物特异性相互作用分析（BIA）已成为现代基因工程技术中的一种先进的手段。与传统的研究方法如酶联免疫吸附测定（ELISA）相比,它具有方便快捷、灵敏度高,应用范围广,实时监控等多项特点,利用这种新型研究手段对于生命科学的基础研究。医学诊断以及治疗等方面有着十分重的意义。本粗略概括了近几年来利用SPR生物传感器进行基础研究的基本情况以及对其的改进,并简要分析了此项技术的优点以及发展前景。     

Nitric oxide inhibition decreases bleomycin-detectable iron in spleen,bone marrow cells and heart but not in liver in exercise rats

The possible role of nitric oxide on the exercise-induced changes in bleomycin-detectable iron (BDI) in the liver, spleen, bone marrow cells and heart was investigated. Female Sprague—Dawley rats were randomly assigned to four groups: S1 (Sedentary), S2 (Sedentary + L-NAME [N-nitro-L-arginine methyl ester]), E1 (Exercise) and E2 (Exercise + L-NAME). Animals in the E1 and E2 swam for 2 h/day for 3 months. L-NAME in the drinking water (1 mg/ml) was administrated to rats in the S2 and E2 groups for the same period. At the end of the 3rd month, nitrite and nitrate (NOx), BDI and non-heme iron (NHI) contents in the liver, spleen, bone marrow cells and heart were measured. The ratio of BDI/NHI was calculated. The exercise induced a significant increase in NOx and BDI contents and/or BDI/NHI ratio in the spleen, bone morrow cells and heart. Treatment with L-NAME, an inhibitor of NOS, led to a significant decrease in NOx and an increase in BDI levels and BDI/NHI ratios in these tissues. The correlative analysis showed that there is significantly positive correlation between NOx levels and BDI contents and/or BDI/NHI ratios in the spleen, bone marrow cells and heart. These results suggest that the increased nitric oxide might be one of the reasons leading to the increased BDI levels in these tissues in the exercised rats. In contrast to the above tissues, in the liver, exercise led to a significant decrease rather than increase in BDI levels and BDI/NHI ratios with a significant increase in NOx contents. Treatment with L-NAME led to a significant increase in BDI levels and BDI/NHI ratios and a decrease in NOx contents in the tissue. These findings plus the results reported by others imply that nitric oxide might have an inhibitory effect on BDI in the liver.