Ishihara T, Yokota N, Hisanaga S, Fujimoto S, Hirayama N, Kato J, Kitamura K, Eto T
First Department of Internal Medicine, Miyazaki Medical College, Kiyotake, Japan.
Clin Nephrol. 1999 Aug;52(2):119-23.
Adrenomedullin (AM), a novel vasodilator peptide, is produced by C-terminal amidation reaction of AM-glycine. AM-glycine, an intermediate form of AM (iAM), is processed from pro AM. AM circulating in the human blood stream was found to consist of an amidated mature form (mAM) and iAM. Biological activity is exerted only by mAM.
To investigate the pathophysiological role of mAM in renal disease, we measured plasma concentrations of mAM as well as total AM (tAM), representing both mAM and iAM, in patients with various renal diseases. In addition, plasma ANP level was measured in all patients.
The concentrations of plasma mAM in renal failure with dialysis (2.1 +/- 0.2 fmol/ml, mean +/- SEM) and without dialysis (1.2 +/- 0.2) were significantly (p < 0.05) higher than those in control group (0.5 +/- 0.1). However, the plasma ANP level was increased only in renal failure patients with dialysis. Plasma mAM levels were significantly correlated positively with serum creatinine levels and negatively with hematocrit. No significant difference was noted in the ratio of mAM/tAM between renal failure patients and healthy subjects.
These results suggest that plasma mAM is increased in renal failure in relation to deterioration of renal function, while the amidation process of AM seems to be unaffected in patients with renal failure.
肾上腺髓质素（AM）是一种新型血管舒张肽，由AM - 甘氨酸经C末端酰胺化反应产生。AM - 甘氨酸是AM的一种中间形式（iAM），由前体AM加工而来。在人体血液循环中发现的AM由酰胺化成熟形式（mAM）和iAM组成。只有mAM具有生物活性。
为研究mAM在肾脏疾病中的病理生理作用，我们测定了各种肾脏疾病患者血浆中mAM以及代表mAM和iAM两者的总AM（tAM）的浓度。此外，还测定了所有患者的血浆心钠素（ANP）水平。
透析的肾衰竭患者血浆mAM浓度（2.1±0.2 fmol/ml，均值±标准误）和未透析的肾衰竭患者血浆mAM浓度（1.2±0.2）显著高于对照组（0.5±0.1）（p < 0.05）。然而，仅透析的肾衰竭患者血浆ANP水平升高。血浆mAM水平与血清肌酐水平显著正相关，与血细胞比容显著负相关。肾衰竭患者与健康受试者之间mAM/tAM比值无显著差异。
这些结果表明，肾衰竭时血浆mAM水平升高与肾功能恶化有关，而肾衰竭患者AM的酰胺化过程似乎未受影响。
