摘要
目的以内源性锂作为肾脏近端小管钠重吸收的标志物,探讨哇巴因-高血压鼠肾脏钠转运情况及在高血压发病机制中的作用。方法将40只180～220g雄性Sprague-Dawley(SD)大鼠随机分为正常对照组(n=20)和哇巴因组(n=20)。每日给予对照组大鼠腹腔注射生理盐水1ml/(kg·d),哇巴因组大鼠腹腔注射哇巴因27.8μg/(kg·d),每周测量收缩压及体重各1次。分别于饲养2和6周后分两批处死动物。收集各组血清及24h尿,测定血清和尿钠、钾、锂和肌酐浓度,计算内生肌酐清除率(Ccr)、钠排泄分数(FENa)、锂排泄分数(FELi)、尿锂钠比(ULi/UNa)、尿钾钠比(UK/UNa)及远端肾小管钠重吸收率(FDRNa)。结果2周后,哇巴因组血压与对照组相比差异无显著性(P>0.05),4周后哇巴因组血压显著高于对照组(P<0.01)。2组体重在各时间段差异均无显著性(P>0.05)。2和6周哇巴因组大鼠的Ccr和FENa与对照组相比差异无显著性(P>0.05);2、6周哇巴因组大鼠的FELi、ULi/UNa、UK/UNa及FDRNa均显著低于对照组(P<0.05,P<0.01,P<0.001)。结论哇巴因-高血压鼠肾脏近端小管钠重吸收增加,且发生于血压升高之前,提示肾脏近端肾小管钠重吸收增加可能是哇巴因引起大鼠血压升高的机制之一。
Objeetive To investigate renal sodium handling of ouabain-hypertensive rats and the role of renal sodium handling in pathogenesis of hypertension using endogenous trace lithium as a marker of proximal sodium reabsorption. Methods Forty male Sprague-Dawley （SD） rats weighting 180 - 220 g were equally divided into normal control group and ouabain group randomly. Rats were infused with normal saline 1 ml/ （kg·d） or ouabain 27.8 μg/ （kg·d） intraperitoneally once a day respectively. Systolic blood pressure （SBP） and body weight were recorded weekly. Rats were sacrificed after 2 and 6 weeks respectively. Blood and 24 hour urine sample were collected to measure the serum and urinary concentration of sodium, potassium, trace lithium, and ereatinine. Endogenous ereatinine clearance rate （Cer）, fractional excretions of sodium （FENa）, and fractional excretions of lithium （FELi）, the ratios of urinary lithium to sodium （ULi/UNa）, the ratios of urinary potassium to sodium （UK/UNa）, and fractional reabsorption of sodium in the postproximal tubules （FDRNa） were also calculated. All were studied on their normal diet and ate salt freely. Results Blood pressure had no significant difference in these two groups after 2 weeks （P 〉 0.05）; After 4 weeks, however, blood pressure was significantly higher in ouabain group than in control group （P 〈 0.01）. Body weight of rats had no significant differenceduring the experiment period （P 〉 0.05）. Ccr and FENa were similar in these 2 groups （P 〉 0.05）. FELi, ULi/UNa, UK/UNa, and FDRNa of ouabain group were significantly lower than control group after 2 and 6 weeks （P 〈 0.05, P 〈 0.01, P 〈 0.001 respectively）. Conclusion The reabsorption of sodium increases in the proximal tubule in ouabain-hypertensive rats, and such increase occurs before the development of hypertension. Therefore, increase of proximal reabsorption of sodium may be involved in the pathogenesis of ouabain-induced hypertension.
出处
《中国医学科学院学报》
CAS
CSCD
北大核心
2005年第4期461-465,共5页
Acta Academiae Medicinae Sinicae
基金
陕西省自然科学研究基金(2004C213)~~
