Proximal tubular angiotensinogen in renal biopsy suggests nondipper BP rhythm accompanied by enhanced tubular sodium reabsorption
Proximal tubular angiotensinogen in renal biopsy suggests nondipper BP rhythm accompanied by enhanced tubular sodium reabsorption
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DOI：
10.1097/hjh.0b013e328353e807
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发表时间：
2012-07-01
影响因子：
4.9
通讯作者：
Kobori, Hiroyuki
中科院分区：
文献类型：
--
作者：
Fukuda, Michio;Urushihara, Maki;Kobori, Hiroyuki
目的：肾小球超滤系数的降低和小管钠重吸收（FRNa）的增强损害了肾脏的钠排泄能力，导致非滴式昼夜血压（BP）节律。体循环中的血管紧张素II可以很容易地通过肾小球毛细血管壁过滤，刺激肾近端小管血管紧张素原（PT-AGT）的产生，导致肾内血管紧张素II的激活，这在动物模型中已知会增加FRNa。方法：我们对40例连续的原发性IgA肾病（IgAN）患者进行了免疫组织化学研究，以确定PT-AGT对FRNa和非滴度昼夜血压节律增强的贡献。结果：IgAN患者PT-AGT免疫染色较对照组升高（P=0.04），且与FRNa （r=0.39， P=0.01）、昼夜血压比（r=0.38， P=0.02）直接相关，与肌酐清除率无关（r=-0.008， P=0.9）。夜/日BP比值由肌酐清除率（r=-0.36， P=0.03）和FRNa （r=0.47， P=0.006）决定。结论：肾内血管紧张素II刺激肾小管钠重吸收，如PT-AGT所示，并参与非俯仰血压节律的发生。对于肾活检显示PT-AGT升高的患者，预防钠潴留的治疗是否有用，需要进一步的研究来评估。
Objectives: The renal capacity for sodium excretion is impaired by a reduction in the glomerular ultrafiltration coefficient and ay enhancement of the fractional tubular sodium reabsorption (FRNa), leading to a nondipper circadian blood pressure (BP) rhythm. Angiotensin II in the systemic circulation can be easily filtered across the glomerular capillary walls and stimulates renal proximal tubular angiotensinogen (PT-AGT) production, leading to the activation of intrarenal angiotensin II, which is known to augment the FRNa in animal models.Methods: We performed an immunohistochemical investigation to determine the contribution of PT-AGT to enhancement of FRNa and the nondipper circadian BP rhythm in 40 consecutive patients with primary IgA nephropathy (IgAN).Results: Immunostaining for PT-AGT was increased in the IgAN patients compared with control individuals (P=0.04), and correlated directly with the FRNa (r=0.39, P=0.01) and the night/day ratio of BP (r=0.38, P=0.02), but not creatinine clearance (r=-0.008, P=0.9). The night/day ratio of BP was determined by both creatinine clearance (r=-0.36, P=0.03) and FRNa (r=0.47, P=0.006).Conclusion: Tubular sodium reabsorption is stimulated by intrarenal angiotensin II, as indicated by PT-AGT, and contributes to the genesis of the nondipper BP rhythm. Further studies are needed to evaluate whether or not treatment to prevent sodium retention is useful for patients who exhibit increased PT-AGT in renal biopsies.