慢性低氧时牦牛和迁饲黄牛颈动脉体组织形态的比较

目的对牦牛、迁饲黄牛及低海拔黄牛颈动脉体(CB)形态及CB中低氧相关因子的表达进行比较,探讨高原土生或迁饲动物CB适应慢性低氧的模式。方法采集青海地区海拔3000~4000m的9头牦牛、2500m的9头高山迁饲黄牛及甘肃平原海拔1300米的12头低海拔黄牛的CB,固定、切片、染色后行光学显微镜和电子显微镜比较观察,并对CB中低氧诱导因子-1α(HIF-1α)、一氧化氮合酶(NOS)、瘦素受体(LEPR)、促红细胞生成素(EPO)等低氧相关因子的表达进行免疫组织化学观察。结果相比黄牛,牦牛CB体积较小,不同海拔牦牛的CB大小、形态及主细胞数量差异无显著性,而迁饲黄牛CB体积较低海拔黄牛大。牦牛CB主细胞中明细胞、暗细胞和固缩细胞的数量百分比比例为67.1%∶28.2%∶4.7%,迁饲黄牛为78.5%∶18.6%∶2.9%,低海拔黄牛为87.3%∶10.2%∶2.5%;与低海拔黄牛相似,牦牛CB少部分明细胞胞质透亮,暗细胞胞核染色质较致密并呈粗颗粒状,而迁饲黄牛CB大部分明细胞胞质透亮,暗细胞胞核染色质致密,颗粒稀少。3种牛支持细胞形态差异无显著性。与低海拔黄牛相比,迁饲黄牛CB主细胞的少数核异染色质增多,个别形态异常,胞质内多数细胞器肿胀溶解,残留少量细胞器和致密核心囊泡。3种牛CB中均有不同程度的HIF-1a、NOS、LEPR、EPO的蛋白表达,其中牦牛CB中EPO蛋白表达阳性率较低海拔黄牛明显降低(P0.05)。结论海拔高度不是影响牦牛颈动脉体大小和主细胞数量的主要因素。迁饲黄牛CB主细胞中细胞类型的比例与牦牛有趋同性改变,但缺氧时行使功能的I型细胞功能系统受损,尚处于低氧环境下的习服阶段。慢性低氧可能主要影响牦牛和迁饲黄牛CB中EPO蛋白表达。     

牦牛与迁饲黄牛及低海拔黄牛肺动脉干及肺组织形态的比较

目的:对牦牛和迁饲黄牛及低海拔黄牛肺动脉干与肺组织形态进行比较研究,获得高原土生或迁饲动物慢性低氧时适应进化的模式。方法:采集青海地区海拔3000~4000m的牦牛、2500 m的高山迁饲黄牛及甘肃平凉1300 m的低海拔黄牛的肺动脉干及肺组织,固定、切片、染色后行光镜和电镜比较观察。结果:55%的迁饲黄牛和98%牦牛肺动脉干中膜以弹性纤维及胶原纤维为主,而45%的迁饲黄牛和100%低海拔黄牛以弹性纤维及平滑肌增多为主,且平滑肌增多成团分布。牦牛和迁饲黄牛肺浆膜结构致密,间皮下以弹性纤维为主,而低海拔黄牛肺浆膜结构疏松,间皮下以胶原纤维为主。相比于迁饲黄牛,牦牛和低海拔黄牛肺终末细支气管黏膜纵行皱襞更明显,牦牛肺呼吸性细支气管黏膜上皮为单层或假复层柱状上皮,多数细胞可见到纤毛,并且黏膜仍有皱襞形成;而黄牛主要为单层柱状上皮,部分细胞可见纤毛。迁饲黄牛肺内小动脉血管壁和微动脉管壁厚度增加,与牦牛及低海拔黄牛比较差异有统计学意义。结论:牦牛肺动脉干和肺组织形态与结构有适应高原的独特形式,迁饲黄牛在适应高原时发生了与牦牛一样的趋同性改变,同时又兼具低海拔黄牛的特点。     

γ-干扰素受体在山羊颈动脉体的表达

目的:检测γ-干扰素受体(IFNGR)在雌性山羊颈动脉体中是否存在,探讨γ-干扰素(IFN-γ)是否可以影响山羊颈动脉体的活动。方法:采用免疫组织化学SP法,观察IFNGR在山羊颈动脉体内的分布特点;利用IPP 6.0图像半定量分析系统分析IFNGR在颈动脉体实质细胞和非实质细胞上的表达量差异。结果:在颈动脉体内IFNGR免疫阳性产物广泛分布,在Ⅰ型细胞、Ⅱ型细胞、血管内皮细胞和神经纤维均有不同程度的阳性染色。IFNGR强阳性产物分布在实质细胞(Ⅰ型细胞和Ⅱ型细胞)中;中等或强阳性产物分布在颈动脉体小叶间的血管内皮细胞中;弱阳性产物分布在小叶内的血管内皮细胞中;图像分析表明,IFNGR在实质细胞的相对表达量与非实质细胞结构相比差异有统计学意义。结论:颈动脉体的实质细胞(Ⅰ型细胞和Ⅱ型细胞)可能是IFN-γ作用的主要靶细胞,提示IFN-γ可能通过位于颈动脉体的Ⅰ、Ⅱ型细胞上的IFNGR,影响Ⅰ、Ⅱ型细胞对动物机体血液中的化学信息的感知和传递,实现IFN-γ对心血管功能的调节。     

牦牛心室蒲肯野纤维的立体分布和结构特点

目的 探讨牦牛心室普肯耶纤维的分布和结构特点,为高原哺乳动物心室传导系统的研究积累形态学资料。 方法 采用墨汁灌注、ABS树脂灌注铸型,石蜡切片HE染色、Masson染色和免疫组织化学染色技术,观察60只成年牦牛的心室普肯耶纤维分布及结构特征。结果 牦牛心室普肯耶纤维束周围包绕有结缔组织鞘。左束支在室间隔内膜下层有2条或3条分支;右束支经隔缘肉柱在右前乳头肌根部心肌层中有3条或4条分支。心室普肯耶纤维在心内膜下层呈多边形网状分布,并在心肌层中发出大量分支,左、右心室乳头肌顶端内膜下层未观察到普肯耶纤维分布。普肯耶纤维呈卷轴状、蜂窝状、漏斗状或脊状构型。Cx43在普肯耶纤维呈膜阳性。结论ABS树脂灌注铸型技术能用于心室普肯耶纤维分布的研究。牦牛心脏左束支和右束支呈不对称分布,左束支较发达。     

中华鳖肾组织微细结构的性别差异

目的 探讨雌、雄中华鳖肾组织的微细结构特征及意义。方法 利用甲苯胺蓝半薄切片和透射电镜超薄切片技术,研究20只雌、雄中华鳖肾脏组织结构。结果 雌、雄中华鳖肾脏肾小管的近端小管和中间段上皮细胞结构存在一定差异,表现在雄性的近端小管立方上皮细胞之间含有侧细胞间隙,基底膜与基膜之间存在基底细胞间隙。侧细胞间隙内分布有由质膜形成的指状突起,细胞基底间隙中分布由基底膜形成的基底迷路。雌性近端小管立方上皮细胞间无侧细胞间隙和基底间隙。雌、雄鳖的中间段上皮细胞也表现出与近端小管立方上皮细胞相似的形态差异,即雄性肾小管的中间段立方上皮细胞间存在侧细胞间隙和基底间隙,间隙内分布有细长的指状突起,而在雌性肾小管的中间段上皮中无侧细胞间隙和基底间隙。雄性中华鳖近端小管上皮细胞有3种：主细胞、秃头细胞和基底细胞;与雄性不同,雌性的近端小管上皮仅有亮、暗两种上皮细胞。结论 雌、雄中华鳖肾脏近端小管和中间段的上皮组织结构存在性别差异。侧细胞间隙和基底间隙仅存在于雄性近端小管和中间段上皮细胞之间,上皮组织细胞之间的侧面间隙与细胞基底间隙应与物质运输有关,提示雄性近端小管的尿液重吸收能力和中间段上皮的尿液浓缩能力可能较雌性的强。     

成年牦牛松果体的光镜和电镜观察

目的 探讨成年牦牛松果体形态结构特征,为哺乳动物松果体形态结构研究积累资料.方法 光镜HE染色、浸银染色和透射电子显微镜技术.结果 光镜下,牦牛松果体由松果体细胞、少量的神经胶质细胞、毛细血管和神经等组成.电镜下,松果体细胞电子致密度低,细胞质内含丰富的线粒体、粗面内质网、滑面内质网、微管、微丝和核糖体;高尔基复合体数量极少,典型异质细胞器突触带呈球形,多位于质膜附近.神经胶质细胞的细胞质内含丰富的线粒体,其胞体突起呈球形膨大伸入到松果体细胞之间.松果体细胞以及神经胶质细胞间均存在突触和连接复合体.牦牛松果体内毛细血管为连续型,其远腹侧血管周围可见色素细胞.结论 成年牦牛松果体细胞内存在神经上皮样和腺上皮样2种细胞连接方式.毛细血管为连续型.松果体细胞内细胞器发达,但很少观察到高尔基复合体.     

高原成人颈动脉体的光镜观察和体视学研究

目的：研究高原成人颈动脉体的形态特征。方法：对２８例不同海拔高度无明显呼吸和循环系统疾病成人死者的颈动脉体（ＣＢ）进行光镜观察,并用Ｗｅｉｂｅｌ建立的正测试格点计数法,对其主细胞和支持细胞进行体视学研究。结果：高原组主细胞和支持细胞的体密度（Ｖｖ）、面密度（Ｓｖ）和面数密度（ＮＡ）明显高于平原组（Ｐ＜００１或Ｐ＜００５）,比表面（δ）明显低于平原组（Ｐ＜００１或Ｐ＜００５）。结论：高原成人ＣＢ主细胞和支持细胞明显增生,表现为数量增多,体积增大,且随着海拔高度增加而增加。     

不同年龄牦牛睾丸蛋白基因产物9.5和神经肽Y的分布比较

目的 探讨蛋白基因产物9.5(PGP9.5)和神经肽Y(NP-Y)在不同年龄牦牛睾丸的分布特征。方法 采取睾丸摘除术收集3~4月龄睾丸9对,3、4岁牦牛睾丸10对,10~12岁牦牛睾丸7对,常规石蜡包埋、切片,免疫组织化学SP法观察PGP 9.5和NP-Y在不同年龄牦牛睾丸的分布特点。结果 PGP 9.5和NP-Y显著分布于幼龄及青年牦牛睾丸Leydig细胞及间质血管周围或血管壁内,两者在青年牦牛睾丸初级精母细胞为阴性,其余生精细胞为阳性;且阳性信号在睾丸体最强,其次为头部,尾部最弱;各年龄段Sertoli 细胞中NP-Y为阳性表达,PGP 9.5均为阴性;老龄牦牛睾丸血管PGP 9.5阳性信号明显,而NP-Y基本无表达。结论 青年牦牛睾丸组织PGP 9.5及NP-Y的显著分布对睾丸生殖功能调节发挥着重要的调控作用;提示NP-Y在老龄牦牛睾丸血管的分布显著降低。     

血管内皮生长因子B在牦牛间脑和脑干相关组织的表达与定位

目的 了解牦牛间脑和脑干不同区域血管内皮生长因子B(VEGF-B)的表达及分布特征,探讨其与低氧适应性之间的关系。方法 选取5头健康牦牛,按照脑大体解剖结构进行分区并采集间脑和脑干相关组织,具体包括垂体、丘脑、下丘脑、延髓和脑桥5个部位。利用Real-time PCR、Western blotting及免疫组织化学技术对VEGF-B在牦牛间脑和脑干相关区域的表达与定位进行研究。结果 牦牛间脑和脑干相关组织中VEGF-B mRNA表达水平最高的部位为垂体,显著高于其他部位(P<0.05),其余表达水平依次为下丘脑、丘脑和延髓,脑桥表达量最低;牦牛间脑和脑干相关组织VEGF-B蛋白表达水平除丘脑高于下丘脑外,其余部位表达水平与mRNA表达趋势一致。免疫组织化学结果显示,与阴性对照组相比,VEGF-B蛋白阳性物质主要分布于上述各类细胞的胞质。其中,垂体中VEGF-B阳性着色主要表达于嗜酸性细胞中;丘脑和下丘脑中VEGF-B阳性着色主要集中于多形细胞;延髓和脑桥中VEGF-B阳性反应主要集中在神经元胞体中。结论 VEGF-B蛋白在牦牛间脑和脑干中均有表达,可能与其所担负的抗细胞凋亡、“生...     

IL-1的Ⅰ型受体在大鼠颈动脉体中的超微定位

目的 研究IL-1的Ⅰ型受体(IL-1RⅠ)在大鼠颈动脉体内的表达和亚细胞定位。方法 灌流固定的正常大鼠颈动脉体组织,用冰冻置换法包埋,超薄切片,胶体金免疫组织化学染色,电镜下观察。结果 IL-1RⅠ样免疫反应阳性产物主要存在于主细胞,胶体金颗粒分布在胞膜、胞浆和胞浆中的细胞器及细胞核。支持细胞和毛细血管内皮细胞的胞浆中也可见少量免疫胶体金颗粒。结论 IL-1RⅠ在大鼠颈动脉体特别是主细胞中有较强表达,此结果为进一步研究颈动脉体作为细胞因子化学感受器的可能性提供形态学基础。     

Specific localization of manserin peptide in the rat carotid body

The carotid body, located at the bifurcation of the common carotid artery, is a small sensory organ that detects changes in oxygen concentration and plays a vital role in controlling respiration. Although several molecules, such as neurotransmitters and neuropeptides, are involved in the regulation of the respiratory system, their detailed mechanisms have not been established yet. This study identifies that the presence of manserin, a neuropeptide, in the carotid body may play a crucial role in regulating respiration.The carotid bodies of adult Wistar rats were perfused with paraformaldehyde, and the frozen sections were subjected to immunohistochemical analyses. The carotid body comprises two distinct types of cells, neuron-like glomus cells and glial-like sustentacular cells. We used specific antibodies to distinguish the specific location of manserin in the carotid body, which included a tyrosine hydroxylase-positive antibody for glomus cells and an S100 protein antibody for sustentacular cells. Immunofluorescence analysis revealed that while tiny, round signals were exclusively observed in the cytoplasm of glomus cells, no signals were observed in sustentacular cells.Because manserin is believed to be secreted from precursor proteins by the endoproteolytic processing of a large precursor protein called secretogranin II, manserin secretion systems may exist in the carotid body, and thus, behave as potential regulators of respiration in the carotid body.     

Comparative embryology of the carotid body

Vertebrate carotid bodies and related structures (branchial arch oxygen chemoreceptors in fishes, carotid labyrinth in amphibians, chemoreceptors in the wall of the common carotid and its branches in birds) develop in embryos when neural crest cells, blood vessels, and nerve fibers from sympathetic and cranial nerve ganglia invade mesenchymal primordia in the wall of the 3rd branchial arch. This review focuses on literature published since the 1970s investigating similarities and differences in the embryological development of 3rd arch oxygen chemoreceptors, especially between mammals and birds, but also considering reptiles, amphibians and fishes.     

Histological changes associated with ageing of the human carotid body

A qualitative and quantitative histological study was made of the carotid bodies obtained at necropsy from 47 subjects ranging in age from 14 to 100 years. With increasing age there is a loss of more than a third of the amount of glomic tissue with a diminution in the size of the lobules. In young people the basic histological pattern of clusters, composed of cores of chief cells with surrounding rims of sustentacular cells, has commonly superimposed on it prominence of the dark variant of chief cells. In middle-aged subjects there is proliferation of sustentacular cells which appear to merge imperceptibly into fibrosis of the lobules and becomes associated with diffuse or focal infiltrates of lymphocytes.     

Distribution of carotid body type I cells and other periadventitial type I cells in the carotid bifurcation regions of the cat

Summary The bilateral distribution of carotid body type I cells was investigated in five non-pedigree cats by serially sectioning the carotid bifurcation regions. Carotid body type I cells occurred bilaterally in close proximity to the wall of the occipital artery or one of its proximal branches, and less frequently the ascending pharyngeal artery within a division of connective tissue with defineable but irregular borders. Caudally, and separate from the principal mass of carotid body type I cells, isolated groups of periadventitial type I cells were found in seven out of ten specimens lying freely in the connective tissues around the occipito-ascending pharyngeal trunk and the origin of the occipital artery immediately rostral to the carotid bifurcation. Periadventitial type I cells were not observed at the level of the carotid bifurcation but on one occasion these cells were noted caudal to the carotid bifurcation lying adjacent to the wall of the rostral end of the common carotid artery. From our data on four specimens, reconstructions were made of the carotid body. The occurrence and significance of the periadventitial type I cells is discussed.     

The carotid body of the harbour seal (Phoca vitulina richardsi)

Summary The bilateral distribution of carotid body type 1 and 11 cells was investigated in five harbour seals (Phoca vitulina richardsi), by serially sectioning the carotid bifurcation regions. The cells occurred bilaterally in the animals and were also present in one specimen from a sixth animal available for study. The type 1 and 11 cells were located in the space between the internal and external carotid arteries and had a varied relationship to the occipital and condyloid arteries. They lay within a division of connective tissue with irregular but defineable borders and this combination of connective tissue and type 1 and 11 cells constituted the principal mass of the carotid body. The carotid body occurred in a variety of forms: wedge-shaped, crescentic or horse-shoe shaped, or as a discrete oval structure. In some specimens the carotid body had a central neurovascular core of small blood vesels and nerves. The artery to the organ originated from either the external carotid, internal carotid or common carotid arteries. Using an interactive image analysis system in eight specimens, which had been perfusion-fixed at a normal arterial pressure, the mean volume of the carotid body was 1.666±0.45 (SD) mm³. Caudally and separate from the principal mass of the carotid body periadyentitial type 1 and 11 cells were noted in 4 out of 11 specimens in the connective tissues adjacent to the external carotid artery, origin of the occipital, and the rostral part of the common carotid artery and its bifurcation.     

Monoamines and their catabolites in the rabbit carotid body

Monoamines and their metabolites have been measured by high performance liquid chromatography with electrochemical detection, in control rabbit carotid bodies and under several experimental conditions: 1) at different times (3 h, 6 h, 24 h, 48 h) after intravenous injection of reserpine (5 mg/kg); 2) 14 days after sympathectomy; 3) 14 days after section of the carotid sinus nerve. The results were analyzed with probability plotting methods. Dopamine was the most important monoamine in the carotid body (CB) and its variations were very large. It was almost entirely depleted by reserpinization without simultaneous increase in 3,4-dihydroxyphenylacetic acid. Sympathectomy increased dopamine content but did not change noradrenaline content. However data analysis suggested that noradrenaline might be compartmented in two pools: one with a large variance, located in the type I cells was increased after sympathectomy, the other, more constant, located in the sympathetic nerve endings was entirely depleted after sympathectomy. Section of the carotid sinus nerve increased dopamine and noradrenaline and quadrupled the serotonin content of the CB. It is proposed that carotid sinus and sympathetic innervations regulate the monoamine metabolism of the CB.