神经肽Y、瘦素在Ⅱ型糖尿病大鼠垂体中的表达及丝胶的保护作用

目的:观察丝胶对Ⅱ型糖尿病大鼠垂体神经肽Y(NPY)和瘦素(leptin)表达的影响.方法:雄性SD大鼠随机分为正常组、模型组、丝胶组和二甲双胍组.模型组、丝胶组和二甲双胍组均建立链脲佐菌素致Ⅱ型糖尿病模型,以血糖≥16.7 mmol/L为成模标准;丝胶组和二甲双胍组分别于成模后给予丝胶和二甲双胍灌胃35 d.采用酶法检测各组大鼠血糖、免疫组织化学显色和RT PCR观察各组大鼠垂体NPY和瘦素及mRNA的表达.结果:与模型大鼠相比,丝胶组和二甲双胍组大鼠血糖、NPY和瘦素及mRNA表达明显降低,且两组比较无明显差别.结论:丝胶可下调垂体NPY和瘦素的高表达,对Ⅱ型糖尿病垂体损伤具有保护作用;且作用与二甲双胍相当.     

神经肽Y和下丘脑与能量平衡的调节

下丘脑弓形核的神经肽Ｙ（ＮｅｕｒｏｐｅｐｔｉｄｅＹ，ＮＰＹ）神经元在机体能量贮存减少时对维持能量平衡起着重要的调节作用，下丘脑神经元能够表达和释放ＮＰＹ，该神经递质对机体能量平衡的调节起着重要作用，这些神经元的过度兴奋将导致肥胖。胰岛素和Ｌｅｐｔｉｎ抑制该类神经元的兴奋性，糖皮质激素则有增强作用。     

海洛因依赖对大鼠直肠神经肽Y表达的影响

目的探讨海洛因依赖期间大鼠直肠内神经肽Y（NPY）免疫反应阳性细胞的形态学改变。方法选取成年SD大鼠,分为海洛因依赖组、盐水对照组和正常对照组,皮下注射海洛因建立大鼠海洛因依赖模型,取直肠组织用免疫组织化学SABC法及图像分析法进行研究。结果与正常及盐水对照组比较,海洛因依赖组大鼠直肠NPY阳性细胞的细胞数均增多。图像分析显示海洛因依赖期间大鼠直肠内NPY阳性细胞的平均灰度值均低于正常及盐水对照组（P〈0.05）;以17 d时间组最低（P〈0.05）。结论海洛因依赖期间直肠NPY阳性细胞的平均灰度值发生变化,提示NPY合成和分泌增多。     

尿毒症患者血液透析治疗对瘦素和神经肽Y水平的影响

研究尿毒症患者血液透析前后血浆瘦素和血清神经肽Y(NPY)的变化,探讨改善尿毒症营养不良的有效措施.本文尿毒症患者69例,分为3组:低通量纤维素膜透析组(A组)32例,低通量血仿膜F6透析组(B组)21例,F60高通量血滤器透析滤过并血液透析组(C组)16例.对照组18名.用RIA测定患者透析前、后及对照组血浆瘦素及血清NPY水平.结果三组瘦素与NPY水平透析前明显高于对照组(P＜0.01);透析后A、B组瘦素、NPY水平未降低,C组瘦素水平明显降低(P＜0.05),但NPY无显著变化.尿毒症患者存在高瘦素及NPY血症,二者无相关性,都不能通过单纯血液透析清除.利用高通量血滤器进行血液滤过有助于增加瘦素的清除率,改善患者营养状态.     

持续癫痫大鼠行为学和神经肽Y mRNA表达的改变

目的探讨癫痫持续状态（SE）对大鼠情感行为和学习记忆功能的影响及海马组织神经肽Y（NPY）mRNA的表达变化。方法戊四氮诱导大鼠SE，采用抬高迷宫和Morris水迷宫观察大鼠情感反应和学习记忆功能的改变。反转录多聚酶链反应（RT-PCR）方法检测大鼠海马NPYmRNA的表达。结果SE组大鼠在抬高迷宫开放臂中逃避时间延长（P〈0．01），进入次数增多（P〈0．01）；水迷宫中逃避潜伏期延长（P〈0．01），搜寻策略变差（P〈0．05），平台象限游泳时间百分比降低（P〈0．01），穿越平台次数减少（P〈0．01）。同时伴有海马NPYmRNA表达上调（P〈0．05）。结论SE可使大鼠情感行为改变和学习记忆功能受损，NPY可能参与这一变化的病理生理过程。     

足月新生儿脐静脉血瘦素和神经肽Y水平的研究

目的 :探讨足月新生儿脐静脉血瘦素和神经肽Y水平及其临床意义。方法 :采用放射免疫分析测定 1 0 0例足月新生儿脐静脉血瘦素和神经肽Y(NPY)浓度。结果 :足月新生儿脐静脉血瘦素水平 7 1 5±3 72 μg/L ,NPY水平为 1 1 2± 4 2 36ng/L ;女婴组瘦素水平为 9 35± 3 5 1 μg/L ,NPY为 1 38 2 9± 4 2 6 7ng/L ,均明显高于男婴组瘦素水平 (4 95± 2 1 8μg/L)和NPY水平 (85 85± 4 0 39ng/L) ,差异有显著性 (p<0 0 1 )。足月新生儿脐静脉血瘦素与新生儿出生体重、孕妇分娩前身高体重指数 (BMI)呈显著正相关关系 (r分别为 0 6 4 7、0 5 4 7,p<0 0 5 ) ;NPY水平与新生儿体重、孕妇分娩前BMI亦呈正相关 (r分别为 0 5 84 ,0 70 5 ,p <0 0 5 )。结论 :胎儿组织及胎盘产生的瘦素和NPY可能参与了妊娠期胎儿体重增长的调节     

左旋18甲基炔诺酮增加大鼠血清瘦素及下丘脑瘦素受体表达

口服避孕药因具有高效、安全的特点而在临床广泛应用,但随之带来的副作用日益引起学者的重视,如体重增加、月经异常等,关于其引起体重增加的有关研究少见报道。瘦素(leptin)是近年来发现的衡量体脂水平的重要指标,又是连接能量和生殖的桥梁。因此,本研究选用左旋18-甲基炔诺酮(     

神经肽Y在自发性癫痫大鼠海马内过表达

目的探讨自发性癫痫大鼠(SER)海马中,神经肽Y(Neuropeptide Y,NPY)的表达变化。方法 RT-PCR检测自发性癫痫大鼠和正常对照组Wistar大鼠海马中NPY mRNA表达,ELISA试剂盒法检测NPY蛋白浓度变化。结果自发性癫痫大鼠海马中NPY mRNA表达水平和NPY蛋白的浓度比正常对照组Wistar大鼠明显上调(P0.01)。结论 NPY mRNA和蛋白过表达可能与自发性癫痫发生机制有关。     

丝胶对2型糖尿病大鼠胰腺胰岛素PI3K-Akt信号通路的调节作用

目的探讨丝胶是否通过影响胰腺胰岛素PI3K-Akt信号通路发挥降血糖的作用。方法 36只雄性SD大鼠随机分为正常对照组、糖尿病模型组和丝胶治疗组,每组12只。采用高脂高糖饲料喂养联合链脲佐菌素(35mg/kg,2次,1次/d)连续腹腔注射法制作2型糖尿病大鼠模型,模型成功标准是空腹血糖≥11.1mmol/L。模型成功建立后,丝胶治疗组大鼠给予丝胶灌胃35d。采用ELISA法检测大鼠血清脂联素水平,Western blotting法和Real-time PCR法分别检测大鼠胰腺胰岛素受体(IR)、胰岛素受体底物-1(IRS-1)、磷脂酰肌醇-3-激酶(PI3K)和Akt蛋白和mRNA的表达情况。结果与糖尿病模型组比较,丝胶治疗组大鼠血清脂联素水平,胰腺IR、IRS-1、PI3K、Akt蛋白和mRNA的表达明显升高(P0.01,P0.05)。结论丝胶可通过上调糖尿病模型大鼠胰腺IR、IRS-1、PI3K和Akt的表达,改善糖尿病时胰腺胰岛素PI3K-Akt信号转导通路的异常,从而发挥降低血糖的作用。     

化解冲剂对脓毒症大鼠神经肽及细胞因子的调节作用

为阐明传统中医学整体观与现代医学神经内分泌免疫网络学说的一致性。建立了大鼠用人感染模型；动态观察了脓毒症大鼠血浆中β－内啡肽、精氨酸加压素及血管活性肠肽的变化；同时观察了血中单个核细胞分泌肿瘤坏死因子α及白细胞介素６能力的改变；并观察了活化瘀代表方剂“化解冲剂”对上述改变的调节作用。     

Differential effects of methamphetamine on expression of neuropeptide Y mRNA in hypothalamus and on serum leptin and ghrelin concentrations in ad libitum-fed and schedule-fed rats

Relatively little is known concerning the interaction of psychostimulants with hypothalamic neuropeptide systems or metabolic hormones implicated in regulation of energy balance. The present studies tested whether methamphetamine alters the expression of neuropeptide Y (NPY) and agouti-related peptide (AgRP), two important orexigenic neuropeptides, or proopiomelanocortin (POMC), the precursor for the anorexigenic peptide alpha-melanocyte-stimulating hormone, or the secretion of leptin, insulin and ghrelin, concomitant with inhibition of food intake. Female rats were either fed ad libitum (AL) or placed on a scheduled feeding (SF) regimen, with access to food limited to 4 h/day. Administration of (+/-)-methamphetamine (7.5 mg/kg, i.p.) 2 h prior to food presentation significantly inhibited food intake in SF animals, but did not affect intake in AL animals. In a separate study, AL and SF animals were killed just prior to expected food presentation, and expression of NPY, AgRP and POMC mRNAs in hypothalamus was determined using in situ hybridisation; concentrations of leptin, insulin and ghrelin in serum were determined with radioimmunoassays. In saline-treated, SF controls, NPY and AgRP mRNA expression in arcuate nucleus and serum ghrelin were significantly elevated, and serum leptin and insulin were significantly reduced. Methamphetamine reversed the up-regulation of NPY mRNA expression observed in the SF condition, without affecting AgRP mRNA or the serum concentrations of metabolic hormones. However, in AL animals, NPY mRNA expression in arcuate and dorsomedial nuclei was significantly increased by methamphetamine, which also reduced serum leptin and insulin and increased serum ghrelin concentrations. These findings suggest that the inhibition of NPY expression in SF animals may be a mechanism underlying the anorexigenic effect of methamphetamine seen in this condition. The increase in NPY expression produced by methamphetamine in AL animals may be mediated by the ability of this drug to decrease secretion of leptin and insulin and increase secretion of ghrelin.     

Time-dependent effects of neuropeptide Y infusion in the paraventricular hypothalamus on ingestive and associated behaviors in rats

In this study the role of neuropeptide Y (NPY) in the paraventricular nucleus of the hypothalamus (PVN) in the daily regulation of feeding, drinking, locomotor activity, and nestbox occupation was investigated. These behaviors were recorded during and after bilateral infusion of NPY into the PVN of rats during the early (E) or late (L) part of the light phase. Administration of NPY caused a significant increase in feeding behavior at E, but not at L. In contrast to the feeding at E, L feeding was associated with increased water intake following NPY infusion. While locomotor activity was similar in sCSF- and NPY-infused rats at all times of the daily cycle, administration of NPY at L, but not at E increased nestbox occupation during the first few hours of the dark phase. This increased nestbox occupation was not associated with altered food intake or drinking behavior, implying that NPY-treated rats made frequent excursions between nestbox and food hopper/water bottle. Thus, feeding-associated drinking and explorative behavior are time-dependently modulated by NPY in the PVN, independent of locomotor activity.     

丝胶预处理对2型糖尿病大鼠腺垂体内NPY及leptin表达的影响

目的:观察彩色蚕茧提取物-丝胶对2型糖尿病大鼠腺垂体内神经肽Y(NPY)及leptin表达的影响。方法:将36只SD大鼠随机分为正常组、模型组和丝胶预处理组。模型组、丝胶预处理组大鼠均建立链脲佐菌素(STZ)致2型糖尿病动物模型,丝胶预处理组于注射STZ前给予丝胶灌胃35 d。采用酶法检测各组大鼠血糖、免疫组织化学染色和RT-PCR观察各组大鼠腺垂体内NPY和leptin蛋白及mRNA的表达。结果:血糖监测结果显示丝胶预处理组大鼠血糖明显低于模型组(P0.01);免疫组织化学染色结果显示:NPY和leptin免疫阳性产物均为棕黄色颗粒状,免疫阳性细胞均为腺垂体内嗜色细胞,NPY主要位于细胞质,leptin主要位于细胞核。与模型组大鼠相比,丝胶预处理组大鼠NPY和leptin蛋白的表达明显降低(P0.01);RT-PCR结果显示:丝胶预处理组大鼠NPY和leptin mRNA的表达明显低于模型组(P0.01)。结论:丝胶预处理可下调腺垂体内NPY和leptin的高表达,对2型糖尿病腺垂体损伤具有明显的预防作用。     

Effects of acupuncture on chronic corticosterone-induced depression-like behavior and expression of neuropeptide Y in the rats

Repeated injection of corticosterone (CORT) induces dysregulation in the HPA axis, resulting in depression and anxiety. Many studies have shown that acupuncture, which is widely used for the treatment of stress and mental illness, in East Asian countries, is an effective therapeutic intervention for psychosomatic disorders. We investigated the influence of acupuncture therapy on chronic CORT-induced behavioral responses to the forced swimming test (FST) and elevated plus maze (EPM) and expression of neuropeptide Y (NPY) in the rat brain using immunohistochemistry. Male Sprague-Dawley rats were injected with CORT (40 mg/kg, i.p.) once daily for 19 consecutive days. The dysregulation of HPA axis by external injection of CORT was confirmed by measuring the CORT concentration in plasma and the expression level of CRF in hypothalamus. Acupuncture was performed at the PC6 acupoint for 5 min before CORT injection. Acupuncture significantly reduced depression- and anxiety-like behavior and increased NPY expression in the hypothalamus. These results demonstrated that stimulation of the PC6 acupoint suppresses the symptopathology of the hypoactivated HPA axis in chronic CORT-induced rat model of depression.     

Effect of polymorphism on expression of the neuropeptide Y gene in inbred alcohol-preferring and -nonpreferring rats

Using animal models of alcoholism, previous studies suggest that neuropeptide Y (NPY) may be implicated in alcohol preference and consumption due to its role in the modulation of feeding and anxiety. Quantitative trait loci (QTL) analysis previously identified an interval on rat chromosome 4 that is highly associated with alcohol preference and consumption using an F2 population derived from inbred alcohol-preferring (iP) and -nonpreferring (iNP) rats. NPY mapped to the peak of this QTL region and was prioritized as a candidate gene for alcohol-seeking behavior in the iP and iNP rats. In order to identify a potential mechanism for reduced NPY protein levels documented in the iP rat, genetic and molecular components that influence NPY expression were analyzed between iP and iNP rats. Comparing the iP rat to the iNP rat, quantitative real-time polymerase chain reaction detected significantly decreased levels of NPY mRNA expression in the iP rat in the six brain regions tested: nucleus accumbens, frontal cortex, amygdala, hippocampus, caudate-putamen, and hypothalamus. In addition, the functional significance of three previously identified polymorphisms was assessed using in vitro expression analysis. The polymorphism defined by microsatellite marker D4Mit7 in iP rats reduced luciferase reporter gene expression in SK-N-SH neuroblastoma cells. These results suggest that differential expression of the NPY gene resulting from the D4mit7 marker polymorphism may contribute to reduced levels of NPY in discrete brain regions in the iP rats.     

Serum level of leptin and neuropeptide Y in children with mild asthma

Leptin (LEP) and neuropeptide Y (NPY) are involved in the maintenance of energy balance and create regulatory loops on central and peripheral stage between neuropeptides and hormones, additionally regulated by other physiological stimuli. According to data confirming tendency to overweight and obesity in asthmatic children we have examined the influence of mild asthma on neurohormonal balance. 43 children, aged 7-17 years, including 27 steroid naive mild asthmatic children aged (mean+/-SD) 12.3+/-2.6 years and 16 age matched healthy children participated in the study. Serum LEP and NPY levels were measured radioimmunologically (RIA). Serum leptin level in asthmatic children was 2.84+/-2.1 ng/ml and did not differ to that of healthy children -3.49+/-1.65 ng/ml, both in boys (p=0.85) and girls (0.49). Similarly, we did not observe any differences between NPY levels in asthmatic (113.5+/-31.1 micromol/ml) and healthy (98.5+/-21.9 micromol/ml (p=0.17)), irrespective to sex. Significant correlations between leptin levels and body mass index (BMI) in asthmatics (r=0.62, p=0.01) and healthy children (r=0.56, p=0.02) were observed. We conclude, that mild asthma in children seems not to affect neurohormonal regulation of energy balance.     

红景天苷对糖尿病并发骨质疏松大鼠瘦素表达的影响

目的： 观察探讨红景天苷（SDS）对糖尿病并发骨质疏松大鼠瘦素表达的影响。方法： 将60只雌性SD大鼠随机分为对照组(A组)、模型组（B组）、SDS低剂量组（C组,18 mg·kg-1·d-1）、SDS高剂量组（D组,36 mg·kg-1·d-1）,相应干预后,于11、16周末断颈取血,测血糖、胰岛素（INS）、瘦素（LP）浓度,取下丘脑测神经肽Y（NPY）含量,取胫骨测骨密度（BMD）。结果：C、D组与B组相比,血糖明显下降（P<0.05）,血清INS、LP浓度及胫骨BMD水平明显升高（P<0.05）,下丘脑NPY含量明显下降（P<0.01）;16周末与11周末相比,C组下丘脑NPY含量变化不明显（P>0.05）;D组下丘脑组织NPY含量及胫骨BMD水平明显升高（P<0.01）。结论：SDS可能通过促进INS 分泌和提高INS 敏感性,来加强血浆LP对骨代谢的外周正性作用;长期大量应用还可能通过作用于血脑屏障而抑制LP对骨代谢的中枢负性影响,从而对糖尿病骨质疏松症起治疗作用。     

Hypothalamic neuropeptide Y and plasma leptin after long-term high-fat feeding in the rat

The ingestion of fat by rodents affects the level of neuropeptide Y (NPY) in the hypothalamus and we hypothesized that they might be linked via leptin, the adipose tissue hormone. The influence of fat intake on leptin and NPY levels was studied in rats fed on either a high-fat (HF) or a low fat diet (LF) for 5 months. Ingestion of the HF diet increased fat deposition (+48%; P < 0.01), leptinemia (+189%; P < 0.001) and reduced NPY levels in the arcuate nucleus (-35%; P < 0.01) and in the paraventricular nucleus (-22%; P < 0.01). However, although leptin levels reflected the amount of relative fat deposition (r = 0.62; P < 0.01), we found no evidence for a direct relationship between plasma leptin and NPY levels in the hypothalamus. These results suggest that the long-term effects of fat intake on NPY concentrations in the hypothalamus and plasma leptin are associated with different regulatory mechanisms.