Interaction of neuropeptide Y receptors (NPY1, NPY2 and NPY5) with somatostatin on somatostatin-induced feeding behaviour in neonatal chicken

1. The present study was conducted to investigate whether brain somatostatin increases feed intake in neonatal chickens. The mediating role of neuropeptide Y receptors on feed intake induced by somatostatin was investigated.

2. In this study, seven experiments were designed, each with four treatment groups (n = 44 in each experiment). In Experiment 1, chicks received control solution and 0.5, 1 and 2 nmol of somatostatin through intracerebroventricular (ICV) injection. In experiments 2, 3 and 4, chickens were ICV injected with control solution and 1.25, 2.5 and 5 μg of B5063 (NPY₁ receptor antagonist), SF22 (NPY₂ receptor antagonist) and SML0891 (NPY₅ receptor antagonist), respectively. In experiment 5, 6 and 7 chickens received ICV injection of B5063, SF22, SML0891, with a co-injection of + somatostatin, control solution and somatostatin. The cumulative feed intake was measured until 120 min post injection.

3. Somatostatin significantly increased feed intake in FD3 chicks. Both B5063 and SML0891 dose-dependently decreased feed intake compared with the control group, while SF22 led to a dose-dependent increase in feed intake. In addition, the hyperphagic effect of somatostatin significantly decreased with co-injection of B560 plus somatostatin (p < 0.05), but SF22 and SML0891 had no effect on feed intake induced by somatostatin in chicks (p > 0.05).

4. Based on the results of this study, it is likely that somatostatin increased feed intake and NPY₁ receptor acts as a mediator in hyperphagic effect of somatostatin in neonatal chicks.     

神经肽Y对犊牛肝细胞PEPCKmRNA丰度及其活性的影响

取单层培养36 h生长良好的犊牛肝细胞.采用单因素重复试验,分别添加0、50、100、200、500、1 000 ng/L的羊体外合成神经肤Y(Neuropeptide Y,NPY),每个处理3个重复(每个重复2孔),再培养12 h后分别提取RNA和制备细胞上清液.应用荧光定量PCR方法检测外源NPY对肝细胞糖异生关键酶磷酸烯醇式丙酮酸羧激酶(Phosphoenolpyruvate carboxykinase,PEPCK)基因表达的影响,同时用比色法检测其对肝细胞PEPCK活性的影响.结果表明,一定浓度的NPY显著促进肝细胞PEPCK mRNA表达,增强了PEPCK活性.     

雏鸵鸟睾丸的结构及睾丸内神经肽Y的表达

采用光镜和电镜技术,观察雏鸵鸟睾丸的显微和超微结构;采用免疫组织化学方法对NPY在睾丸内的表达进行研究,探明NPY在睾丸内的表达规律.光镜下可见,雏鸵鸟睾丸表面有一层由坚韧的结缔组织构成的白膜,它向睾丸实质内形成的结缔组织不发达,不形成睾丸纵隔和睾丸小隔;雏鸵鸟的曲精小管直径为85～90 μm,生精上皮由支持细胞和1～2层生精细胞构成,此时精原细胞已开始分裂增殖,可见明显的分裂相,初级精母细胞数量少,体积大.电镜下可见,精原细胞胞质内有少量线粒体、游离核糖体和内质网;初级精母细胞富含线粒体、游离核糖体、内质网和溶酶体;支持细胞与精原细胞之间界限清晰,胞质内含较多游离核糖体,其他细胞器不发达;间质细胞的胞核形状不规则,内含较多脂滴.免疫组化显示,NPY在曲精小管周围、睾丸小血管周围、精母细胞和睾丸间质内均有表达,在睾丸小血管周围和精母细胞内表达量较高,而在曲精小管周围和睾丸间质内表达量较低.     

Comparison of the Distribution of PGP9.5 and NPY in Cryptorchidism and Testicular Tumors in Dogs

The purpose of this study was to analyze the distribution and expression of peptidergic neurotransmitters protein gene product 9.5 (PGP9.5) and neuropeptide Y (NPY) in cryptorchidism and testicular tumors of dogs,compare them with normal testicular tissues of the same age,and provide reference for clinical diagnosis of malignant transformation in testicular tumors of dogs.HE staing,Masson trichrome staining,Gomori silver staining and toluidine blue staining were used to observe the tissue characteristics of reticular fibers,collagen fibers and mast cells.Immunohistochemical SP method and immunofluorescence combined with IPP were used to analyze the expression and localization of PGP9.5 and NPY in tissues.The results showed that the seminiferous epithelium of normal dog testis was composed of 4-7 layers of spermatogenic cells and Sertoli cells,and the distribution of collagen fibers and reticular fibers in interstitial tissue was sparse.The thickness of collagen fibers in the basement membrane of cryptorchidism seminiferous tubules increased,the nucleus of Sertoli concentrated at the base of seminiferous tubules,and the interstitial reticular fibers increased.The tissue structure of testicular tumor was unclear,collagen fibers and reticular fibers were irregularly distributed,and mast cells increased significantly compared with normal and cryptorchid groups.The immunofluorescence results showed that PGP9.5 was moderately positive in Leydig cells of normal testis,no significant expression in spermatogenic cells,strongly positive in Leydig cells and spermatogenic cells of cryptorchidism,and occasional expression in testicular tumors.NPY was occasionally expressed in normal testicular Leydig cells,but not in spermatogenic cells,strong positive expression in Leydig cells and seminiferous epithelium of cryptorchidism,high density and strong positive expression in interstitial vessels,and no obvious expression in testicular tumors.Immunohistochemical statistics showed that the expression of PGP9.5 and NPY in testicular tumor tissue were extremely significantly lower than that in normal group (P<0.01),while the expression of PGP9.5 and NPY in cryptorchidism group were significantly or extremely significantly increased (P<0.05;P<0.01).Therefore,the expression of PGP9.5 and NPY in cryptorchidism of dogs was increased suggesting that the cryptorchidism of dogs had a tendency to develop into a tumor,and was related to the degree of malignant transformation of tumor.     

产前营养水平对奶牛产后干物质摄入量、产乳量及血浆神经肽(NPY)影响的研究

将围产期健康奶牛30头随机分为三组，分别于产前第28d开始饲喂标准日粮、营养水平增加20％日粮和营养水平降低20％日粮，产后各组奶牛均饲喂标准泌乳日粮，直至产后第56d试验结束。试验结果表明，产前低营养饲喂不仅提高了产后奶牛干物质摄入量、产乳量，而且提高了产后奶牛血浆NPY的浓度。     

犬隐睾及睾丸肿瘤中PGP9.5和NPY的分布比较

试验旨在分析肽能神经递质蛋白基因产物9.5（protein gene product 9.5,PGP9.5）和神经肽Y（neuropeptide Y,NPY）在犬隐睾及睾丸肿瘤中的分布和表达,并与同年龄正常睾丸组织进行比较,为认识犬睾丸肿瘤恶变临床诊断提供参考。应用HE染色、Masson三色染色、Gomori银浸染、甲苯胺蓝染色观察各组织中网状纤维、胶原纤维及肥大细胞等组织特征,采用免疫组织化学SP法及免疫荧光法结合IPP统计分析PGP9.5和NPY在组织中的表达及定位。结果显示,正常犬睾丸生精上皮由4~7层生精细胞及Sertoli细胞构成,间质组织胶原纤维和网状纤维分布稀疏。隐睾生精小管基底膜胶原纤维厚度增加,Sertoli细胞核浓缩位于生精小管基底,间质网状纤维增多。睾丸肿瘤组织结构不清晰,胶原纤维和网状纤维无规则分布,肥大细胞较正常组及隐睾组显著增多。免疫荧光定位表明,PGP9.5在正常睾丸Leydig细胞中呈中等阳性表达,生精细胞中无明显表达;隐睾Leydig细胞及生精细胞中呈强阳性表达;睾丸肿瘤中偶有表达。NPY在正常睾丸Leydig细胞中偶见阳性表达,生精细胞中无表达;隐睾Leydig细胞及生精上皮中无表达,间质小血管管壁呈高密度强阳性表达;睾丸肿瘤组织中无明显表达。免疫组化统计表明,睾丸肿瘤组织中PGP9.5和NPY较正常组极显著降低（P<0.01）,隐睾组PGP9.5和NPY表达显著或极显著增加（P<0.05;P<0.01）。因此,犬隐睾时PGP9.5及NPY的表达增高,提示犬隐睾时已有发展为肿瘤的趋势,且与肿瘤恶变程度相关。     

NPY、IGF-1基因对文昌鸡繁殖性状的遗传效应

采用PCR-RFLP技术检测文昌鸡NPY基因和IGF-1基因的多态性,并分析NPY、IGF-1基因对文昌鸡繁殖性能的影响。结果表明:300日龄NPY AA型个体平均产蛋数(88.95枚)与NPY aa型个体平均产蛋数(81.55枚)相比差异显著,NPY基因以加性方式作用,其中300日龄产蛋数加性效应值为-0.252(P<0.05)。IGF-1基因同样以加性方式作用,其中300日龄产蛋数加性效应值为0.199(P<0.05)。300日龄IGF-1 bb型个体平均产蛋数(89.03枚)与IGF-1 BB型个体平均产蛋数(82.61枚)相比差异显著,400日龄IGF-1 bb型个体平均产蛋数(137.84枚)与IGF-1 BB型个体平均产蛋数(127.82枚)相比差异显著;IGF-1 bb型个体平均连产天数(3.38 d)分别与IGF-1的BB、Bb型个体平均连产天数(2.96、2.78 d)相比差异均显著。     

神经肽(NPY)基因多态性与邵伯鸡母系繁殖性状的关联性分析

以神经肽(NPY)基因为候选基因,利用PCR-SSCP技术检测该基因的SNPs,并分析基因多态性与邵伯鸡母系母鸡的开产日龄、开产蛋重、开产体重以及300日龄总产蛋数之间的关联性。结果显示,在NPY基因上发现1个SNP位点,带有1对等位基因A和B,基因频率分别为0.35和0.65;不同基因型仅与开产体重性状间有显著相关,表现为基因型AA个体的平均开产体重比基因型AB个体的平均开产体重重119.03 g,且差异显著(P<0.05),基因型AA个体的平均开产体重比基因型BB个体的平均开产体重重47.6 g,但差异不显著(P>0.05);基因型BB个体的平均开产体重比基因型AB个体的平均开产体重重71.43 g,差异显著(P<0.05)。     

Ghrelin对奶山羊下丘脑神经肽Y(NPY)和刺鼠相关蛋白(AGRP)mRNA表达的影响

研究Ghrelin对奶山羊下丘脑神经肽Y(NPY)和刺鼠相关蛋白(AGRP)mRNA表达的影响。10只泌乳期莎能奶山羊随机分为试验组和对照组,每组5只。试验组静脉注射Ghrelin(3.0μg/kg),3h后宰杀,迅速取下丘脑,检测下丘脑脑神经肽Y和刺鼠相关蛋白mRNA的表达。结果表明,一定剂量的Ghrelin对NPY mRNA的表达具极显著上调作用(P0.01);对AGRP mRNA的表达也有显著促进作用(P0.01)。以上结果提示Ghrelin可能通过对这些神经肽的作用参与对奶山羊摄食和能量代谢等生理活动的调节。