人参皂甙对急性肾衰大鼠的肾保护作用与外周肾小管上皮细胞氮能机制

Renal protective effect of ginsenoside against acute renal failure and nitronergic mechanism in PCT

关键词:  急性肾功能衰竭  人参皂甙  近曲小管  神经元型一氧化氮合酶

Key words:  acute renal failure  ginsenoside  PCT  nNOS

摘要:

［目的］ 探讨人参皂甙对急性肾衰大鼠的肾保护作用与外周肾小管上皮细胞氮能机制。［方法］选用52只健康雄性SD大鼠，随机均分为4组：实验对照组（ARF+NS组）、实验给药组（ARF+GS组）、空白对照组（NS+NS组）和空白给药组（NS+GS组）。采用甘油致急性肾衰的动物模型，通过整体实验和免疫组织化学的方法，观察急性肾衰大鼠口服人参皂甙（25 mg/2 mL）48 h后，肾皮质匀浆丙二醛（MDA）、一氧化氮（NO）水平的变化，同时观察肾小管上皮细胞（PCT）神经原型一氧化氮合酶（nNOS）免疫反应活性的变化。［结果］ ARF+NS组肾皮质匀浆MDA为（10.51±0.16）nmol/mgprot，明显高于NS+NS组（P<0.05）。ARF+GS组肾皮质匀浆MDA为（6.77±0.33）nmol/mgprot，明显低于ARF+NS组（P<0.05）。ARF+NS组肾皮质匀浆NO为（9.35±0.80）μmol/gprot，明显低于NS+NS组（P<0.05）。ARF+GS组肾皮质匀浆NO为（18.63±1.56）μmol/gprot，明显高于ARF+NS组（P<0.05）。免疫组织化学的结果显示ARF+NS组肾近曲小管上皮细胞内nNOS免疫反应阳性颗粒数目和免疫染色强度明显增强（P<0.05）。ARF+GS组肾近曲小管上皮细胞内nNOS免疫反应活性进一步增强，明显高于ARF+NS组（P<0.05）。［结论］ 急性肾衰大鼠口服人参皂甙48 h后，能明显增强肾组织抗氧化损伤的能力和肾保护的作用；肾近曲小管上皮细胞内nNOS免疫反应活性明显增强。肾小管上皮细胞一氧化氮含量的改变，可能是人参皂甙抗急性肾衰和肾保护的作用的外周氮能机制。

Abstract:

［Objective］ To investigate the protective effect of ginsenoside on acute renal failure (ARF) rats and the correlation between the effect and the changes of nNOS-immunoreactivity in proximal convoluted tubules (PCT). ［Methods］Fifty-two male SD rats were randomly divided into four groups: ARF+NS group, ARF+GS group, NS+NS group and NS+GS group. Glycerol-induced acute renal failure in rats was employed. Malondialdehyde (MDA) and nitric oxide (NO) in renal cortex homogenate were measured by commercial regents by experiment in vivo. Meanwhile, the changes of nNOS-IR in the PCT were observed by immunohistochemistry. ［Results］ In ARF rats treated with physiological saline (ARF+NS group), the level of MDA in renal cortex homogenate significantly increased (P<0.05), but NO markedly decreased (P<0.05). However, in ARF rats treated with ginsenoside (ARF+GS group) the level of MDA in renal cortex homogenate significantly decreased, but NO markedly increased(P<0.05). Immunohistochemistry showed an obvious increase of nNOS-IR in the PCT in ARF+NS group (P<0.05), compared with that in NS+NS group; but nNOS-IR was further enhanced in ARF+GS group (P<0.05), compared with that in ARF+NS group. ［Conclusion］ Our results indicated that ginsenoside administrated orally in glycerol-induced ARF rats significantly decreased MDA, increased NO, having a strong antioxidative effect. Our results also indicated that ginsenoside administrated orally could further increase the expression of nNOS-IR in the PCT in ARF rats. Consequently, we provided a new evidence that renal nitronergic neuron in the PCT contributed to the renal protective effect of ginsenoside against acute renal failure.