Ge Heng, Jiang Xin, Ren Yan-ping, Lü Zhuo-ren
Department of Nephrology, Second Affiliated Hospital, Xi'an Jiaotong University College of Medicine, Xi'an 710004, China.
Nan Fang Yi Ke Da Xue Xue Bao. 2010 Sep;30(9):2111-4.
To investigate the role of renal sympathetic nerves in renal sodium transport in ouabain-hypertensive rats (OHR).
Sixteen male SD rats with sham renal denervation (Sham-RDNX) and 16 with renal denervation (RDNX) were randomly into normal control group and ouabain group to receive intraperitoneal injection of normal saline (1 ml/kg) and ouabain (27.8 µg/kg) once a day, respectively. Systolic blood pressure (SBP), heart rate and body weight were recorded weekly. Food consumption of the rats was determined twice a week. After a 4-week treatment, blood and 24 h urine samples were collected to measure the serum and urinary concentration of sodium, trace lithium and creatinine. Endogenous creatinine clearance rate (Ccr), fractional excretions of sodium (FENa), fractional excretions of lithium (FELi) and fractional reabsorption of sodium in the postproximal tubules (FDRNa) were calculated. Plasma renin activity was determined by radioimmunoassay. Norepinephrine was extracted from the renal tissue and assayed for norepinephrine content by HPLC.
The body weight, food intake and heart rate showed no significant difference among the 4 groups (P > 0.05). After 4 weeks, the SBP of control RDNX group (CDNX) was significantly lower than that of the control Sham-DNX group (Csham)(P < 0.05); the SBP of ouabain RDNX group (ODNX) was also significantly lower than that of ouabain Sham-DNX group (Osham) (P < 0.05); RNDX lowered SBP by about 10 mmHg in both ouabain groups and control groups. The SBP was significantly higher in Osham and ODNX groups than in the corresponding control groups (P < 0.01), also significantly higher in ODNX group than in Csham group (P < 0.01). Ccr showed no significant difference among the 4 groups(P > 0.05). FENa, FELi and FDRNa were significantly lower in ouabain groups than in the corresponding control groups (P < 0.05, P < 0.01, P < 0.05), but FENa, FELi and FDRNa of ODNX group were similar with those of Osham group (P > 0.05); FENa , FELi and FDRNa were similar between CDNX and Csham groups (P > 0.05). The plasma renin activity was comparable between the 4 groups (P > 0.05). Renal norepinephrine level was markedly reduced in RDNX group compared with that in Sham-RDNX group in both ouabain and control groups (P < 0.01).
The increase of proximal tubule sodium reabsorption in OHR is not dependent on the renal sympathetic nerve.
研究肾交感神经在哇巴因高血压大鼠（OHR）肾钠转运中的作用。
将16只假肾去神经支配（Sham-RDNX）的雄性SD大鼠和16只肾去神经支配（RDNX）的雄性SD大鼠随机分为正常对照组和哇巴因组，分别每天腹腔注射生理盐水（1 ml/kg）和哇巴因（27.8 µg/kg）一次。每周记录收缩压（SBP）、心率和体重。每周测定两次大鼠的食物摄入量。治疗4周后，采集血液和24小时尿液样本，测定血清和尿液中的钠、微量锂和肌酐浓度。计算内生肌酐清除率（Ccr）、钠排泄分数（FENa）、锂排泄分数（FELi）和近端小管后段钠重吸收分数（FDRNa）。采用放射免疫分析法测定血浆肾素活性。从肾组织中提取去甲肾上腺素，用高效液相色谱法测定去甲肾上腺素含量。
4组大鼠的体重、食物摄入量和心率无显著差异（P>0.05）。4周后，对照RDNX组（CDNX）的SBP显著低于对照假去神经支配组（Csham）（P<0.05）；哇巴因RDNX组（ODNX）的SBP也显著低于哇巴因假去神经支配组（Osham）（P<0.05）；RNDX使哇巴因组和对照组的SBP均降低约10 mmHg。Osham组和ODNX组的SBP显著高于相应的对照组（P<0.01），ODNX组也显著高于Csham组（P<0.01）。4组的Ccr无显著差异（P>0.05）。哇巴因组的FENa、FELi和FDRNa显著低于相应的对照组（P<0.05、P<0.01、P<0.05），但ODNX组的FENa、FELi和FDRNa与Osham组相似（P>0.05）；CDNX组和Csham组之间的FENa、FELi和FDRNa相似（P>0.05）。4组的血浆肾素活性相当（P>0.05）。在哇巴因组和对照组中，RDNX组的肾去甲肾上腺素水平均显著低于Sham-RDNX组（P<0.01）。
OHR近端小管钠重吸收的增加不依赖于肾交感神经。
