study on the changes in peritoneal ultrafiltration in peritoneal dialysis in relation to the regulation of the gene expression of peritoneal aquaporins

腹膜透析中腹膜超滤变化与腹膜水通道蛋白基因表达调控的研究

• 批准号: 10671011
• 负责人: HASEGAWA Hajime
• 金额: $ 1.54万
• 依托单位: Jikei University School of Medicine
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 1999
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10671011/
• 关键词: 腹膜透析; 水チャネル; 遺伝子発現; 限外濾過; 伸展刺激; in situ hybridization; aquaporin; 中皮細胞

Recently, we have found that gene expression of peritoneal aquaporins (AQP1 and 4) was enhanced transitorily at the initial phase of continuous peritoneal dialysis (PD) in rats. To study the involvement of AQP in the ulltrafiltration loss occurred in long term CAPD patients, we designed long term experimental PD for 2 months in rats. Small catheter was settled in the abdominal cavity for exchanging dialysate and sampling.. Physiological saline (for control) or glucose-containing human-use dialysate(1.35% or 4.0%) were administered and exchanged twice a day. Daily monitored effluent volume (ultrafiltration volume) was increased in the initial phase and subsequently fixed, as observed in the previous experiment. Histological changes in the peritoneum such as mesothelium detachment or submesothelial fibrosis were not obvious. The effluent volume was gradually decreased after 5 weeks although we failed to obtain the statistical significance. Gene expression of peritoneal AQP1 and 4 after 8 … More weeks dialysis was inclined to be decreased comparing to that before dialysis (statistically insignificant) studied by RT-PCR combined with ELISA analysis. In situ hybridization study revealed that the signal accumulation in the capillary endothelium was less obvious after 8 weeks dialysis,but it was not significant. To confirm the involvement of AQP in the ultrafiltration failure in patients with long-term CAPD therapy, further study must be required. Next, to study the involvement of mechanical stretch in the induction of AQP gene expression, we designed in vivo and in vitro experiments. For in vivo experiment, small catheter with balloon was settled into the rats abdominal cavity to expand the peritoneum without dialysis. For in vitro experiment, mesothelial cells obtained by mechanical scratch of the peritoneum were cultured on the rubber plate, for subsequent application to 30% statistic stretch or 60 Hz cycled stretch. Peritoneum expansion in vivo generated transient enhancement of AQP gene expression at the day 3, which was similar pattern to that in experimental dialysis. However, there was no significant difference in in vitro experiement, suggesting that indirect effect of peritoneal expansion might be involved in the transient enhancement of AQP gene expression. Clinically, unexpected recovery from ultrafiltration failure in CAPD patients is sometimes experienced after few weeks discontinuation of PD. The peritoneal expansion induced AQP gene expression may be involved in the phenomenone. Less

最近，我们发现大鼠连续腹膜透析（PD）初始阶段腹膜水通道蛋白（AQP1和4）基因表达短暂增强。为了研究AQP在长期CAPD患者超滤功能丧失中的作用，我们设计了为期2个月的大鼠长期实验PD。在腹腔内放置小导管以交换透析液和取样。给予生理盐水（作为对照）或含葡萄糖的人用透析液（1.35%或4.0%），每天更换两次。每日监测出水量（超滤量）在初始阶段增加，随后固定，如前面的实验所观察到的。腹膜组织学改变如间皮脱离或间皮下纤维化不明显。出水量在5周后逐渐减少，但我们没有获得统计学意义。RT-PCR联合ELISA分析透析8周以上患者腹膜AQP1和aq4基因表达较透析前有降低的趋势（差异无统计学意义）。原位杂交研究显示，透析8周后毛细血管内皮的信号积累不明显，但不显著。为了证实AQP在长期CAPD治疗患者超滤衰竭中的作用，还需要进一步的研究。接下来，为了研究机械拉伸对AQP基因表达的诱导作用，我们设计了体内和体外实验。在体实验中，不经透析，将带球囊的小导管置入大鼠腹腔扩张腹膜。体外实验，将腹膜机械划伤获得的间皮细胞培养在橡胶板上，随后进行30%统计拉伸或60 Hz循环拉伸。体内腹膜扩张在第3天产生AQP基因表达的一过性增强，与实验透析相似。然而，在体外实验中没有显著差异，提示腹膜扩张的间接作用可能参与了AQP基因表达的短暂增强。临床上，CAPD患者在停药几周后会出现超滤功能异常的恢复。腹膜扩张诱导AQP基因表达可能参与了这一现象。少