食物摄入与下丘脑能量平衡

能量平衡（energy balance）是能量摄入与能量消耗相平衡的过程。动物机体在处于能量平衡时才能维持正常的生命活动。下丘脑中的多个与摄食相关的神经核团，在神经和体液的调节下发挥关键作用，并构成了复杂而精密的神经网络。本文将从影响下丘脑能量平衡的神经核团、神经肽、神经投射和外周激素等方面，对食物摄入与下丘脑能量平衡进行论述。     

神经肽Y受体在摄食调控中的作用

神经肽Y(NPY)是下丘脑最主要的神经化学信号物质之一,在机体的摄食活动中发挥了重要作用。大量研究表明,NPY可以通过受体介导来刺激食欲。文章主要综述了NPY相关受体在采食调控中的作用,以期为生产实际中调控动物采食量提供理论参考。     

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.     

瘦素调节动物体重的研究进展

瘦素是调节动物体重的重要物质,文章重点阐述了瘦素与其他神经肽的相互作用,瘦素对动物短期采食行为的影响,并就瘦素调节体重过程中所产生的颉颃现象作了分析,最后就瘦素在动物生产上的应用前景及其研究方向作了一些展望和建议。     

神经肽Y与动物的肥胖

神经肽Y是一种由36个氨基酸残基组成的单链多肽,它具有广泛的生理功能,涉及食欲、体重、性行为、生殖功能、能量平衡、神经内分泌功能、心脏血管功能、记忆的保持等调节过程.特别是它具有很强的促进食欲作用,是导致动物肥胖的重要原因之一.本文着重讨论NPY与动物肥胖的关系.     

家蚕Alltostatin及Allatotropin的基因组鉴定与表达特征分析

抑咽侧体神经肽(Allatostatin,AS)和促咽侧体神经肽(Allatotropin,AT)是控制昆虫保幼激素合成的激素.本研究应用BlastP程序,鉴定了家蚕基因组中的AS及AT,并发现它们只有一个拷贝.利用家蚕表达特征的全基因组芯片数据,调查了AS及AT在家蚕的组织和发育表达特征.结果发现,AS在5龄3天至上蔟的发育阶段以及5龄3天的头部组织表达,相反,AT则没有表达,这与保幼激素的活动规律较一致.但AS在中肠的高表达是否有特殊的功能,还有待进一步研究.这些分析为我们深入研究AS及AT在家蚕中的调控机制奠定了基础.     

增食欲素及其生理功能研究进展

<正>近几年,在下丘脑发现了可促进食欲且来源于同一前体的两种新神经肽:增食欲素A和B(orexinA和B),它们可激活两种密切相关且与G蛋白偶联的细胞表面受体(GPCRs)。研究显示它在增加摄食、饮水,调节睡眠觉醒周期、生殖、体温、血压和感觉等方面有广泛作用。本文综述了增食欲素的基因及蛋白质结构、组织分布和功能,以及增食欲素受体,探讨了增食欲素的作用机理,并对其在动物生产中的应用前景作了展望。     

妊振内分泌调控

妊娠期间是动物内分泌最为活跃的阶段之一，体内的各种和生殖相关的激素和信号物质都随之发生变化，除了神经肽类和类固醇激素外，特别是母体和孕体分泌的一些生物活性因子。它们对妊娠都有着特殊重要的意义。深入了解它们在妊娠过程中调控机理，将有利于在生产和科研上进一步的应用。