新生大鼠肾脏缺血损伤对β_1-整合素分布和表达的影响

Study of β_1-integrin in Neonatal Rats with Ischemic Renal Injury

目的 探讨缺血损伤时β1 -整合素在新生大鼠肾脏肾小管上皮细胞中表达的变化及其在组织中的定位。方法 将 2 4只新生 SD大鼠随机分为缺血 10 m in组、缺血 30 m in组和对照组 ,每组各 8只。钳夹缺血组大鼠左侧肾蒂 ,建立肾脏缺血动物模型。对照组不予钳夹。采用免疫荧光法观察新生大鼠肾小管上皮细胞β1 -整合素的分布和表达。结果 对照组β1 -整合素主要分布在新生大鼠肾小管上皮细胞的基底侧 ,在肾小球也可见其染色。缺血 10 min即可出现β1 -整合素的断裂 ,并随缺血时间的延长 ,损伤更加明显。不同视野下计数出现断裂的肾小管数目 ,缺血 10 m in、30 min分别有 2 3%、6 5 %的肾小管有断裂现象 ,与对照组相比差异有显著性 (P<0 .0 5 )。不同缺血时段组间未观察到β1 -整合素整合光密度值的变化 (P>0 .0 5 )。结论 新生大鼠肾脏广泛分布着β1 -整合素。缺血损伤可使β1 -整合素出现断裂。它的这种病理改变可能是导致缺血损伤时肾小管上皮细胞极性消失和脱落的原因之一。

Objective To study the change of β 1-integrin in neonatal rats with ischemic renal injury. Methods Twenty-four neonatal rats weighing from 30 to 40 g were chosen. Anesthesia was carried out by peritoneal injection of nembutal-sodium solution (4 mg/100 g). Renal ischemic injury model was induced by clamping the left renal pedicle for different periods of time. The kidneys of normal neonatal rats were functioned as the control group. Immunofluorescence technique was used to detect the location of β 1-integrin in kidney, especially in cortex. Results In control group, β 1-integrin subunit was found to be located mainly in the basal membrane of tubular epithelial cell. After 10 minutes of ischemia, immunostaining highlighted the broken basement membranes of the experiment groups. The longer the ischemia continued, the more the broken points we observed. There were significant differences between the experiment groups and the control group. Yet, no significant difference in the IOD value of β 1-integrin was seen between the 10-min-ischemia and 30-min-ischemia groups. Conclusion Under physiological condition, β 1-integrin is distributed over the basal membrane of the tubular epithelial cell of neonatal rat. Ischemic injury can cause the changes of β 1-integrin which may be the reason of exfoliation and depolarization of tubular epithelia cell.