Effect of a single hemodialysis session on endothelial dysfunction.
BACKGROUND
The mechanisms of endothelial dysfunction induced by hemodialysis are unclear. To gain a mechanistic view we have evaluated some of the biochemical markers which directly or indirectly lead to endothelial dysfunction during a single dialysis session.


METHODS
Time course changes in plasma nitrate levels, arginine (ARG), citrulline, asymmetric dimethylarginine (ADMA), homocysteine (Hcy), malondialdehyde (MDA) and lipoprotein-associated phospholipase A2 (LpPLA2) were evaluated in 27 patients with end-stage renal disease on maintenance hemodialysis. Statistical evaluation of changes was done using analysis of variance for repeated measures and linear regression using generalized estimating equations for repeated measures.


RESULTS
Nitrate levels significantly increased as a result of dialysis (p<0.001). Hcy (p<0.05) and ADMA (p<0.001) levels were found to be significantly decreased. ARG/ADMA ratio showed an increase (p<0.001). Presence of oxidative stress (OS) was observed in the form of increased plasma MDA levels. Nitrate levels were negatively associated with Hcy, ADMA and LpPLA2 activity.


CONCLUSIONS
Our results show an increased production of nitric oxide (NO) during dialysis, which however is affected by increased OS ultimately favoring endothelial dysfunction. Measures to reduce the OS during hemodialysis are needed to get the complete benefit of clearance of circulating inhibitors of NO synthase during dialysis.
Department of Biochemistry, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India.
Prabhakar Reddy
PR
Errakonda
Ramakrishna
R
Paladugu
Aparna R
AR
Bitla
Suchitra M
SM
Musturu
Jayaseelan
J
Lakshman
Srinivasa Rao V L N
SR
Pemmaraju
Sivakumar
S
Vishnubhotla
D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase / Q000097:blood; D001120:Arginine / Q000031:analogs & derivatives / Q000097:blood; D015415:Biomarkers / Q000097:blood; D002956:Citrulline / Q000097:blood; D004730:Endothelium, Vascular / Q000378:metabolism / Q000503:physiopathology*; D006710:Homocysteine / Q000097:blood; D006801:Humans; D007194:India; D007676:Kidney Failure, Chronic / Q000097:blood / Q000503:physiopathology / Q000628:therapy*; D016014:Linear Models; D008315:Malondialdehyde / Q000097:blood; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000378:metabolism; D018384:Oxidative Stress; D006435:Renal Dialysis / Q000009:adverse effects*; D013997:Time Factors
D015415:Biomarkers; D009566:Nitrates; D006710:Homocysteine; D002956:Citrulline; D009569:Nitric Oxide; D008315:Malondialdehyde; C018524:N,N-dimethylarginine; D001120:Arginine; D043203:1-Alkyl-2-acetylglycerophosphocholine Esterase