小鼠出生后肾脏发育过程中的细胞增殖与凋亡

目的：观察小鼠出生后肾脏发育过程中增殖细胞核抗原(PCNA)的表达及细胞凋亡的特征,探讨出生后小鼠肾脏发育过程中细胞增殖与凋亡的规律及其关系。方法：应用免疫组织化学技术和原位末端标记法(TUNEL法)分别检测小鼠出生后1～70d肾脏中PCNA阳性的细胞和凋亡细胞。结果：小鼠出生后1～70d,皮质中的肾小体、肾小管、髓放线以及髓质中的肾小管和集合管的细胞,早期增殖活跃,随着肾脏发育成熟而表达逐渐减弱。同时,也存在着细胞凋亡现象,且凋亡高峰一般出现在增殖高峰之后。结论：细胞增殖与凋亡在小鼠生后肾脏发育的整个过程中普遍存在,生后1～7d细胞增殖旺盛,增殖高峰之后出现凋亡高峰,生后28～70d两者活动均减弱。     

小鼠肾脏发育中的细胞凋亡

目的：研究小鼠肾脏发育过程中的细胞凋亡规律及形态学特点,方法：应用光镜、电镜技术和TUNEL法分别对不同胚龄、生后日龄小鼠肾脏细胞凋亡进行了观察。结果：皮质凋亡细胞多出现在生肾区S小体之间和是肾小体内,凋亡高峰期在胚龄14－18d之间,髓质凋亡细胞出现在肾小鼠管上皮内,凋亡高峰期在生后7d 左右。超微结构观察可见皮质和髓质凋亡细胞主要表现为核固缩,染色质凝集,细胞皱缩。皮质和髓质凋亡细胞结局为,被邻近细胞吞噬,或脱落到肾小管腔内,结论：小鼠肾脏发育过程中确有细胞凋亡;皮质中细胞凋亡与生肾区的出现和肾小体发育完善有关,髓质中细胞凋亡与髓质中肾小管和集合小0管的有发育完善有关。     

发育期小鼠肾小体细细胞增殖与凋亡的研究

目的研究小鼠肾小体发育过程中细胞增殖与凋亡的变化规律.方法采用PCNA免疫组织化学方法、末端脱氧核苷酸转移酶介导的缺口末端标记法（TUNEL染色法）和光、电镜技术,对发育不同阶段肾小体的细胞增殖和凋亡进行观察.结果 PCNA免疫组织化学染色显示：在Ⅰ和Ⅱ期肾小体内几乎所有细胞PCNA呈强阳性反应,Ⅲ、Ⅳ期肾小体PCNA阳性细胞数逐渐减少,Ⅴ期肾小体PCNA阳性细胞少见.TUNEL阳性细胞多出现在出生前,主要在Ⅲ、Ⅳ期肾小体表达.电镜观察：早期肾小体所有细胞核分裂象机率均高,Ⅲ期肾小体中的内皮细胞、足细胞核分裂象机率高,Ⅳ期肾小体中只见到内皮细胞核分裂象,Ⅴ期细胞核分裂象少见.电镜下所见的细胞凋亡多在Ⅲ、Ⅳ期肾小体,其中以内皮细胞、肾小囊壁层细胞凋亡居多.结论细胞增殖与凋亡行为在小鼠肾小体发育的整个过程中普遍存在,协同参与了调控肾小体正常发育过程.     

小鼠肾发育中的细胞凋亡

目的:探讨小鼠肾发育过程中细胞凋亡的发生规律.方法:在树脂切片上,应用原位末端标记技术,观察昆明小鼠发育不同时期的肾中凋亡细胞的分布及量的变化.结果:在肾发生发育的过程中,肾皮质和髓质内几乎所有结构都有凋亡细胞散在分布.其中,肾小体的凋亡指数在生后14 d达到高峰,而肾小管的凋亡指数从生后7d之后变化不大.同时,髓质中的间质细胞也发生了明显的凋亡变化.结论:伴随着肾各种结构的发生发育而出现的细胞凋亡是肾发育的一个基本特征,此过程延续到生后2周.肾单位的数量虽然在生后7d已经不再增加,但是肾小体结构的成熟和分化还在继续进行,可能将进一步促进肾小体滤过功能的成熟.     

小鼠肾小体的生长曲线

目的:探讨小鼠肾脏发生发育过程中肾小体体积的增长规律。方法：光镜下应用体视学方法对生前和生后小鼠肾脏中各发育阶段的肾小体体积进行测量。结果：胚龄14d时，逗号小体和S小体出现，生后7d消失。胚龄16d时，Ⅲ、Ⅳ期肾小体出现，其体积从胚龄16d到生后40d大约增大70倍。结论：小鼠肾小体于胚龄14d发生，从生后7d到生后40d体积增长迅速。     

表皮生长因子对小鼠肾小管发育中细胞增殖的影响

目的:观察小鼠肾小管发育中细胞增殖和表皮生长因子(EGF)的表达特征,探讨 EGF 对小鼠肾小管发育中细胞增殖的影响.方法:应用 5-溴-2-脱氧尿嘧啶(BrdU)标记增殖细胞.应用免疫组织化学、免疫荧光、免疫印迹技术并结合体视学方法检测生后 1、3、5、6、7、14、21、28、40 d 小鼠肾小管 BrdU 阳性细胞和 EGF 的表达.结果:EGF 于生后6 d表达在肾小管上皮细胞,之后随着日龄的增加表达渐增;BrdU 阳性细胞于生后1 d表达,14 d达高峰,之后随着日龄增加而逐渐减少;生后14 d之后 EGF 与细胞增殖表达趋势完全相反.结论:推测 EGF 在生后小鼠肾发育中对肾小管的分化和成熟起重要作用,但并不促进细胞增殖.     

成纤维细胞生长因子受体1,2在小鼠肾发育中的动态表达

背景：在肾发育过程中，成纤维细胞生长因子受体1,2的时空表达仍是一个有争议的问题，且其与肾脏发育的关系尚不清楚。目的：观察成纤维细胞生长因子受体1,2在小鼠肾发育过程中的动态表达，探求它们与肾发生发育的关系。方法：培育不同发育阶段的胎鼠(E12,14,16,18 d)和仔鼠(N1,3,7,14,24,40 d)，应用免疫组织化学技术观察成纤维细胞生长因子受体1,2在不同肾组织中的时空表达，结合体视学和Western blot对它们的表达进行定量分析。结果与结论：(1)免疫组化显示：在E12 d时，成纤维细胞生长因子受体1主要定位在输尿管芽尖端的生后肾组织，随后表达在各期未成熟的肾小体、部分远曲小管和毛细血管袢，反应部位主要集中在生肾区；而成纤维细胞生长因子受体2开始即在输尿管芽和生后肾组织中均有表达，随着后肾发育，定位于未发育成熟的各期肾小体、远端小管、集合管和髓袢细段，成熟肾小体表达微弱；(2)体视学和Western blot检测显示：成纤维细胞生长因子受体1在生前表达较高，出生后逐渐下降，N7 d后表达很低；成纤维细胞生长因子受体2在肾脏的表达随着胚(日)龄的增加而升高，N7 d后...     

Slit2在小鼠肾脏发育过程中的表达

目的观察并检测Slit2在小鼠肾脏发生发育过程中的定位和表达变化,探索Slit2对肾脏发生发育的调节作用。方法分别选取胚龄(E)12、14、16、18天胎鼠和生后(N)1、7、14、21、40天仔鼠,每组随机选取10只。胚龄12天取全胚,其余各组胎鼠或小鼠剖腹取肾脏,制备石蜡切片和提取蛋白。通过免疫组织化学技术系统观察小鼠肾脏Slit2的表达和定位;通过蛋白印迹技术检测各组小鼠肾脏Slit2的表达变化。结果Slit2在胚龄12天肾脏的生肾区即开始表达。其中,Slit2在输尿管芽明显表达,在生后肾组织中仅在输尿管芽周围的间充质聚集部位表达,其余部位并无广泛表达。随着肾脏的发育,Slit2在肾小体发育的逗号小体阶段、S小体阶段有较强的表达,在Ⅲ期肾小体阶段,Ⅳ期肾小体阶段及成熟肾小体阶段有微弱的表达。在肾脏早期髓质出现后,Slit2在近端小管、远端小管和集合管均有表达。Slit2表达量从胚龄14天到胚龄16天轻度增加,从胚龄16天到生后40天逐渐减少。结论 Slit2在发育各阶段的肾小体、发育及成熟期的泌尿小管中均有表达,提示其对肾小体和泌尿小管的发育可能具有重要的作用。     

血管紧张素Ⅱ受体1和受体2在小鼠肾脏发育中的表达

目的观察小鼠肾脏发育中血管紧张素Ⅱ受体1(AngiotensinⅡreceptor type1,AT_1)和受体2 (AT_2)的表达特征,探讨小鼠肾脏发育过程中AT_1和AT_2的作用及相互关系。方法应用免疫组织化学技术、免疫印迹法(Western blot)并结合体视学方法检测胚龄12、14、15、16、18d及生后日龄1、3d小鼠肾脏发育中AT_1和AT_2的表达。结果AT_1和AT_2均首先出现在输尿管芽,然后出现在肾小管,生后表达逐渐减弱。早期肾小体内AT_2丰富表达,随着肾小体的成熟表达量逐渐降低。结论在小鼠肾脏发育中,AT_1可能与输尿管芽分支不断延长以及肾小管的增殖密切相关,AT_2可能与输尿管芽和肾小体的相互诱导相关。     

小鼠肾脏发生发育的形态计量学研究

目的　探讨小鼠肾脏胚胎及生后发生发育规律。方法　应用光镜连续切片技术结合体视学定量分析方法。结果　皮质出现的时间为胚龄 14日 ,早期髓质结构出现在胚龄第 18日。皮质生肾区在生后 7日消失 ,生后 2 1日出现髓质内带。体现学分析结果说明 :髓质主要在生后发育完善 ,皮质体积在生后快速增大 ,肾小球的数目在生后 7日前发育完毕。结论　小鼠肾脏单位的发育是从胚胎后期 ,即胚龄 14日开始进行的 ,至生后 7日完成。胚胎 18日始到生后 2 1日是髓质发育期     

小鼠肾近端小管的三维重建

目的 研究小鼠肾近端小管三维空间走行的特点及规律。 方法 C57/BL/6J小鼠3只,灌流固定后取肾组织块并树脂812包埋,垂直肾长轴连续半薄切片,从肾被膜到肾外髓外带共得到1 200张2.5μm厚的连续切片,显微镜下获取数字图像,计算机配准,C语言编程,追踪并三维重建58条近端小管走行。 结果 在皮质迷路中,近端小管起始段在离开肾小球后,均先向被膜方向走行约100～1 400μm后返折,在各自肾小球周围盘曲并占据相对独立的区域,很少和其他肾单位近端小管曲部区域重合。浅表皮质肾单位与中间皮质肾单位的近曲小管盘曲紧密,所占空间比近髓肾单位近曲小管小。在髓放线中,近端小管直部的走行有明显的层次：来源于浅表皮质肾单位的近端小管直部走行于中央,来源于皮质深部肾单位的近直小管则依次走行在其外围,皮质最深层的肾单位的近直小管几乎无直部。所有近端小管均止于肾外髓外带与内带的交界处,并移行为髓袢降支细段。 结论 小鼠近端小管的起始段、曲部和直部在皮质迷路与髓放线都有各自走行区间,其吡邻关系及所处生物学环境不同,这对肾近端小管不同节段对不同物质转运功能的生理及病理评估提供形态依据。     

小鼠肾小管发育过程中纤维粘连蛋白与整合素α5的表达

背景：纤维粘连蛋白-整合素α5相互作用影响肾小管发育的体内研究较少。 目的：观察小鼠肾小管发育过程中纤维粘连蛋白及其受体整合素α5的表达。 方法：选取胚龄(E)12,14,16,18 d和生后日龄(P)1,3,7,14,21,28,40 d的小鼠。 结果与结论：免疫组织化学染色结果显示纤维粘连蛋白于E12 d时即表达于输尿管芽的基底膜处,随后表达于发育各个时期的肾小管基膜;整合素α5于E12 d时开始表达,表达部位是肾小管的上皮细胞。体视学测量结果显示纤维粘连蛋白表达的面密度值和整合素α5表达的体密度值都随肾脏的发育逐渐增大。Western blot结果显示纤维粘连蛋白和整合素α5蛋白的水平都随肾脏的发育逐渐增加。可见纤维粘连蛋白和整合素α5在小鼠肾小管的发育和成熟过程中的表达具有一定的时空性,对肾小管的发育起一定的作用。     

Renal anatomy of the manatee,Trichechus manatus,linnaeus

The manatee kidney is com posed of several closely apposed lobes. These are formed by cortical folds (plicae corticales) that completely isolate the medullae, except where the medullae of adjacent lobes are partially fused. The cortex is continuous; its folds usually are separated, but only partially, by interlobar septa ex tending from the renal capsule. The cortex makes up ～57% of renal mass in adults and 68% in the calf. There are about 3 million glomeruli per kidney. The average is somewhat less than that expected of an adult eutherian of equal mass. The glomeruli, however, are large; they form 7.38%±1.33 of cortical mass, which is above that for at least ten unrelated adult eutherians. The number of glomeruli per gram of cortex is considerably greater in the calf than in the adult. The medullae are about 43% of renal mass. The cortico-medullary thickness ratio is 0.08 to 0.24. All terminal collecting ducts open at a crater (cra-tera cribrosa) of varying depth. Hair-pin loops occur at all levels of medulla, and apparently all loops bend at their thick segment. Cortical loops occur in the medullary rays. Vascular bundles were evident at the cortico-medullary border and thin tubules extended into the medulla from the central ends of the medullary rays (cortical) in seven out of the nine kidneys. The renal pelvis is separated from the central ends of the cortical folds by delicate fascia through which pass the interlobar vessels. There are no fornices and no infundibula. The collagenous tissue of the pelvic wall extends across most of the pelvic surface of the outer medulla.     

Scanning and transmission EM of rat kidney following low dose mercuric chloride administration.

The development of necrosis and the subsequent regeneration of the proximal tubular epithelium located in the cortex and the outer medulla of the rat kidney following subcutaneous injection of 2 mg of mercuric chloride per kilogram of body weight was observed utilizing light micromicroscopy (LM), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). The cortical proximal tubules were largely free of injury. In the medullary proximal tubules, the residual, undamaged cells underwent a change in phenotype appearance involving loss of the microvillus border, a decrease in cell height, and an increase in cytoplasmic ribosomes. These cells phagocytosed luminal debris. With time the cell height gradually increased, specialized organelles returned, and the luminal microvilli progressed from short, sparse profiles, to tufts of longer microvilli and finally the brush border was completely reformed. Some kidneys contained calcified tubules which regenerated more slowly than damaged but uncalcified tubules. Similarly, the medullary segments of the proximal tubules regenerated more slowly than the juxtamedullary region. Clusters of epithelial cells were occasionally seen growing into the tubular lumina during regeneration. Marked intersitial leukocyte infiltrations were observed.     

Cell proliferation and morphometric changes in the rat kidney during postnatal development

We have investigated the temporal maturation of the rat kidney during the postnatal developmental period. As a result, we observed the following: an active process of cortical cell proliferation and differentiation occurs as late as day 20. The medulla is the most immature zone at birth and displays the greatest morphological changes during this period. At birth, no distinction exists between inner and outer medulla, and the outer and inner strip of the outer medulla can be distinguished as late as day 30. Remodeling of the ECM surrounding collecting ducts occurs in the medulla twice, stopping at day 11 and it occurs in the papilla three times, stopping at day 20. The increase of kidney size is temporally different for each kidney zone. The cortex and the papilla acquire the morphological appearance of the adult kidney before the medulla does. Consequently, the medulla remains at the highest degree of immaturation among the kidney zones for a relatively long postnatal period.     

Oxidative stress and induction of heme oxygenase-1 in the kidney in sickle cell disease

Chronic nephropathy is a recognized complication of sickle cell disease. Using a transgenic sickle mouse, we examined whether oxidative stress occurs in the sickle kidney, the origins and functional significance of such oxidant stress, and the expression of the oxidant-inducible, potentially protective gene, heme oxygenase-1 (HO-1); we also examined the expression of HO-1 in the kidney and in circulating endothelial cells in sickle patients. We demonstrate that this transgenic sickle mouse exhibits renal enlargement, medullary congestion, and a reduced plasma creatinine concentration. Oxidative stress is present in the kidney as indicated by increased amounts of lipid peroxidation; heme content is markedly increased in the kidney. Exacerbation of oxidative stress by inhibiting glutathione synthesis with buthionine-sulfoximine dramatically increased red blood cell sickling in the sickle kidney: in buthionine-sulfoximine-treated sickle mice, red blood cell sickling extended from the medulla into the cortical capillaries and glomeruli. HO activity is increased in the sickle mouse kidney, and is due to induction of HO-1. In the human sickle kidney, HO-1 is induced in renal tubules, interstitial cells, and in the vasculature. Expression of HO-1 is increased in circulating endothelial cells in patients with sickle cell disease. These results provide the novel demonstration that oxidative stress occurs in the sickle kidney, and that acute exacerbation of oxidative stress in the sickle mouse precipitates acute vaso-occlusive disease. Additionally, the oxidant-inducible, heme-degrading enzyme, HO-1, is induced regionally in the murine and human sickle kidney, and systemically, in circulating endothelial cells in sickle patients.