肾脏分泌髓质素I需要氧气。

Muirhead E E, Brooks B, Byers L W

Department of Pathology, University of Tennessee, Memphis 38163.

J Hypertens. 1992 Sep;10(9):963-7.

OBJECTIVE

To test the hypothesis that the secretion of medullipin I by the kidney involves an oxidative step.

DESIGN

Medullipin I is secreted by kidney renomedullary interstitial cells and is converted to medullipin II by the liver. Medullipin I can be derived from the kidney in the renal venous effluent by perfusing normal rat kidneys with 95% O2- 5% CO2 at an elevated pressure (180 mmHg). To evaluate whether the secretion of medullipin I involves an oxidative step normal rat kidneys were perfused at an elevated pressure in the presence of O2, in the absence of O2 and after treatment of the kidneys with a powerful antioxidant.

METHODS

Normal rat kidneys were perfused with 5% albumin bubbled with O2-CO2 at 180 mmHg. This was the control procedure for each of the three approaches. In approach (1), the kidneys were perfused with 5% albumin bubbled with N2. In approach (2), the kidneys were perfused with 'blood' treated with carbon monoxide. In approach (3), the kidneys were treated with the antioxidant butylated hydroxytoluene then perfused with 5% albumin bubbled with O2-CO2. Each perfusate was tested for medullipin I activity by rapid intravenous injection into the SHR.

RESULTS

All three approaches, which exclude the action of molecular O2, prevented the secretion of medullipin I by the kidneys.

CONCLUSION

The secretion of medullipin I by the kidneys involves an oxidative step.

目的

验证肾脏分泌髓质素I涉及氧化步骤这一假说。

设计

髓质素I由肾脏肾髓质间质细胞分泌，并在肝脏中转化为髓质素II。通过在高压（180 mmHg）下用95% O₂ - 5% CO₂灌注正常大鼠肾脏，可在肾静脉流出液中从肾脏获得髓质素I。为评估髓质素I的分泌是否涉及氧化步骤，在有氧、无氧条件下以及用强效抗氧化剂处理肾脏后，对正常大鼠肾脏进行高压灌注。

方法

用在180 mmHg下经O₂ - CO₂鼓泡的5%白蛋白灌注正常大鼠肾脏。这是三种方法各自的对照程序。方法（1）中，用经N₂鼓泡的5%白蛋白灌注肾脏。方法（2）中，用经一氧化碳处理的“血液”灌注肾脏。方法（3）中，先用抗氧化剂丁基化羟基甲苯处理肾脏，然后用经O₂ - CO₂鼓泡的5%白蛋白灌注。通过快速静脉注射到SHR中，对每种灌注液进行髓质素I活性检测。