Ethylene glycol induced hyperoxaluria increases plasma and renal tissue asymmetrical dimethylarginine in rats: a new pathogenetic link in hyperoxaluria induced disorders.
OBJECTIVE
The pathogenesis of kidney stones remains elusive. There is some evidence that hyperoxaluria may effect vascular endothelium and many studies link renal stones to atherosclerosis. Also, renal vascular endothelial cells regulate proximal tubular epithelial cell function. We determined the effect of hyperoxaluria on plasma and tissue levels of asymmetrical dimethylarginine. The secondary aim was to determine the effect of verapamil on asymmetrical dimethylarginine.


METHODS
A total of 42 Sprague-Dawley rats were included in the study. In groups 1A, 1B and 1C hyperoxaluria was induced with ethylene glycol for 2 weeks. Groups 2A, 2B and 2C received ethylene glycol for 14 days and verapamil for 28 days. Control group 3 received no specific medication but distilled water. Blood samples were obtained at 24 hours and at study end, and kidney samples were obtained at 24 hours, and 7 and 28 days for histopathological evaluation.


RESULTS
Plasma asymmetrical dimethylarginine increased early in the hyperoxaluric group (p = 0.0002). The effect was retained at the end of the study period (p = 0.01). There was no increase in asymmetrical dimethylarginine in the verapamil group on short-term and long-term followup. Hyperoxaluria induced a significantly dense staining pattern in renal tissue asymmetrical dimethylarginine vs controls (p = 0.01). Asymmetrical dimethylarginine staining did not differ in the control and verapamil groups.


CONCLUSIONS
Increased systemic and local tissue asymmetrical dimethylarginine may help explain the pathogenetic mechanisms of hyperoxaluria induced disorders such as nephrolithiasis and atherosclerosis.
Aydin
Hasan
H
Department of Internal Medicine, Section of Endocrinology and Metabolism, Yeditepe University Medical Faculty, Istanbul, Turkey. haydin@yeditepe.edu.tr
Yencilek
Faruk
F
Mutlu
Nilgün
N
Comunoğlu
Nil
N
Koyuncu
Hasbey Hakan
HH
Sarica
Kemal
K
D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives* / Q000097:blood / Q000378:metabolism; D019855:Ethylene Glycol / Q000008:administration & dosage; D006959:Hyperoxaluria / Q000097:blood / Q000139:chemically induced / Q000209:etiology* / Q000378:metabolism* / Q000517:prevention & control; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution; D014700:Verapamil / Q000627:therapeutic use
C018524:N,N-dimethylarginine; D001120:Arginine; D014700:Verapamil; D019855:Ethylene Glycol