Suda T, Osajima A, Iwamoto M, Anai H, Tamura M, Kabashima N, Ota T, Watanabe Y, Kanegae K, Okazaki M, Nakashima Y
Second Department of Internal Medicine, University of Occupational and Environmental Health, School of Medicine, Kitakyushu, Japan.
Clin Nephrol. 2002 Jun;57(6):444-51. doi: 10.5414/cnp57444.
Adrenomedullin (AM), a hypotensive and natriuretic peptide, consists of an amidated mature form (mAM) and an intermediate form in human plasma, of which only mAM exerts biological activity. Like atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), plasma levels of mAM are reported to be significantly elevated in hemodialysis (HD) patients, suggesting that mAM may be stimulated partly by increased body fluid volume in a manner similar to the natriuretic peptides. Here, we examined the relationship between mAM levels and ANP or BNP levels and the effect of HD on plasma mAM in HD patients.
We measured plasma levels of mAM, total AM (tAM), ANP and BNP before and after HD in patients on long-term HD (n = 22, mean age 56.3 +/- 3.2 years) using radioimmunoassay.
Baseline mAM (2.7 +/- 0.3 fmol/ml) and tAM (23.6 +/- 2.0 fmol/ml) were significantly higher in HD patients than in healthy subjects (1.1 +/- 0.2 fmol/ml, 9.0 +/- 2.1 fmol/ml, respectively). HD significantly reduced the levels to 1.2 +/- 0.2 fmol/ml and 13.8 +/- 1.4 fmol/ml, respectively, although tAM levels were still elevated compared to healthy subjects. Similar plasma ANP and BNP levels were obtained in HD patients. There were significant correlations between mAM and tAM levels before and after HD and between HD-induced changes in mAM and tAM levels. In the pre-HD state, levels of both mAM and tAM correlated significantly with BNP levels, but the correlation of BNP with mAM was closer than that with tAM. In contrast, no correlations were observed between the 2 forms of AM and ANP. Changes in mAM levels during HD also correlated significantly with BNP but not ANP levels, although the changes in tAM did not correlate with those of the 2 natriuretic peptides.
Our results suggest that the secretion/metabolism of mAM may be regulated in a manner similar to that of BNP in HD patients.
肾上腺髓质素（AM）是一种具有降压和利钠作用的肽，在人血浆中由酰胺化的成熟形式（mAM）和中间形式组成，其中只有mAM具有生物活性。与心房利钠肽（ANP）和脑利钠肽（BNP）一样，据报道血液透析（HD）患者的mAM血浆水平显著升高，这表明mAM可能部分受到与利钠肽类似的体液量增加的刺激。在此，我们研究了HD患者中mAM水平与ANP或BNP水平之间的关系以及HD对血浆mAM的影响。
我们使用放射免疫分析法测量了长期HD患者（n = 22，平均年龄56.3±3.2岁）HD前后血浆中mAM、总AM（tAM）、ANP和BNP水平。
HD患者基线mAM（2.7±0.3 fmol/ml）和tAM（23.6±2.0 fmol/ml）显著高于健康受试者（分别为1.1±0.2 fmol/ml、9.0±2.1 fmol/ml）。HD后mAM和tAM水平分别显著降至1.2±0.2 fmol/ml和13.8±1.4 fmol/ml，尽管与健康受试者相比tAM水平仍升高。HD患者的血浆ANP和BNP水平相似。HD前后mAM和tAM水平之间以及HD引起的mAM和tAM水平变化之间存在显著相关性。在HD前状态，mAM和tAM水平均与BNP水平显著相关，但BNP与mAM的相关性比与tAM更密切。相反，两种形式的AM与ANP之间未观察到相关性。HD期间mAM水平的变化也与BNP显著相关，但与ANP水平无关，尽管tAM的变化与两种利钠肽的变化无关。
我们的结果表明，HD患者中mAM的分泌/代谢可能以与BNP类似的方式受到调节。
