【摘要】 目的:观察小鼠出生后肾脏髓质发育中Bcl-2和Bax基因表达与细胞凋亡的关系。方法:实验于2004-03/2005-03在锦州医学院组织与胚胎学教研室完成。取成年健康昆明系小白鼠24只,体质量25～30g,雌雄(3∶1)同窝饲养。见雌鼠阴道栓出现计为胚龄0天。对孕鼠饲养2周后,每日早8时、晚5时观察生产情况,以观察到仔鼠出生的最早时间计为生后0天,分别取生后1,3,7,14,21,28,70d的仔鼠各4只。经乙醚麻醉后,取出肾脏,制成切片5μm。每个标本分别选取经肾门的薄片做连续切片,根据切片的多少等间隔选取4张切片,每张切片系统随机选取5个视野,采用原位末端标记法光镜下观察阳性细胞所占的百分比。细胞凋亡指数=凋亡阳性细胞数/细胞总数×100%。同时免疫组织化学方法,对生后小鼠肾脏髓质发育中的Bcl-2和Bax基因蛋白表达进行观察。结果:纳入小白鼠24只,均进入结果分析。①在小鼠出生后肾脏髓质发育的过程中,TUNEL阳性细胞均有不同程度的表达。小鼠出生后第1天,细胞凋亡指数为(32.46±3.69)%,于生后第7天达到高峰,细胞凋亡指数为(45.36±4.35)%,以后随着日龄增加凋亡细胞逐渐减少;在70d成年小鼠肾脏中,TUNEL阳性细胞少见。②小鼠出生后第1天,Bcl-2/Bax比值较高,两者的比值为(1.15±0.23)%;从第3天开始Bcl-2/Bax比值有所减少,于第7天降到最低,为(0.27±0.08)%。以后两者的比值又逐渐回升,并达到最高值(2.87±0.35)%。结论:Bcl-2/Bax比值的降低可能是肾脏髓质发育过程中细胞凋亡指数逐渐升高的机制之一。更多还原

【Abstract】 AIM: To investigate the relationships between the expressions of Bcl-2 and Bax genes in the renal medullary during postnatal development in mice and apoptosis. METHODS: The experiment was performed in the Department of Histology and Embryology, Jinzhou Medical College from March 2004 to March 2005. Twenty-four Kunming mice (the ratio of female and male was 1:3) with the body mass ranged 25-30 g were bred together. Embryonic 0 day was termed as the pessary fell off. Pregnant mice were fed for 2 weeks and observed twice each day respectively at 8.00 PM and 5.00 AM, while the neonatal 0 day was termed as mice were born. The mice after birth 1, 3, 7, 14, 21, 28 and 70 days were selected, with 4 mice in each time point, and mice were anesthetized to obtain the kidneys, so as to cut into 5 μm sections. The reniportal section of each sample was made into serial sections, and 4 sections were selected according to the intervals, while 5 field of views were selected randomly in each section. The terminal deoxynucleotidyl transferase mediated dUTP-biotin nick endlabeling(TUNEL staining method) was adopted to observe the percentage of positive cells under the light microscope. Apoptotic index = TUNEL positive cells/ total cells×100%. At the same time, Bcl-2 and Bax protein expressions in renal medullary in postnatal development were studied by immunohistochemical methods. RESULTS: A total of 24 enrolled mice were involved in the analysis of results. ① The TUNEL positive cells differently expressed in the renal medullary in mice during postnatal development. The apoptotic index was (32.46±3.69) % on the first day after birth, and it peaked on the 7th day after the birth, which was (45.36±4.35)%, while the apoptotic cells decreased gradually time increasing. And TUNEL positive cells were not found in the kidney of 70-day old adult mice. ② On the first day after the birth, the ratio of Bcl-2 and Bax was as high as(1.15±0.23)%, while it decreased since the third day, and it was the lowest on the seventh day, which was (0.27±0.08)%. Then the ratio began to increase gradually and peaked at (2.87±0.35) %. CONCLUSION: The decrease of ratio between Bcl-2 and Bax might be an important mechanism of increased TUNEL positive cells in renal medullary during postnatal development.更多还原