Fasudil, a Rho-kinase inhibitor, reverses L-NAME exacerbated severe nephrosclerosis in spontaneously hypertensive rats.
BACKGROUND
In this study, we tested the hypothesis that long-term Rho-kinase inhibition would reverse nitro-L-arginine methyl ester-exacerbated nephrosclerosis in spontaneously hypertensive rats and attempted to elucidate the mechanism involved.


METHODS
Five groups (each n = 8) were studied: untreated spontaneously hypertensive rats; nitro-L-arginine methyl ester (50 mg/l in drinking water, for 3 weeks)-treated spontaneously hypertensive rats; nitro-L-arginine methyl ester with fasudil (10 mg/kg/day)-treated spontaneously hypertensive rats; nitro-L-arginine methyl ester for 3 weeks followed by fasudil for 3 weeks-treated spontaneously hypertensive rats (same doses), and nitro-L-arginine methyl ester for 3 weeks followed by untreated for 3 weeks. We examined renal function, blood pressure, histological features, oxidative stress markers, and mRNA expression in the renal cortex.


RESULTS
Nitro-L-arginine methyl ester-treated spontaneously hypertensive rats had higher blood pressure, proteinuria, and serum creatinine and lower creatinine clearance, urinary NO3/NO2 ratio, and urinary cGMP excretion compared with control spontaneously hypertensive rats (all Ps < 0.05). Nitro-L-arginine methyl ester-treated spontaneously hypertensive rats also had increased free radical metabolites and abnormal morphological findings with increased nicotinamide adenine dinucleotide phosphate oxidase activity, phosphorylation of myosin phosphatase targeting subunit-1, and mRNA expression of RhoA, RhoB, RhoC, collagen I and III, transforming growth factor-beta, nicotinamide adenine dinucleotide phosphate subunit, endothelial nitric oxide synthase, plasminogen activator inhibitor, and intercellular adhesion molecule-1 in the renal cortex compared with control spontaneously hypertensive rats. Long-term co-treatment with fasudil slightly improved these indices, but most of them were not statistically significant. Late fasudil treatment significantly improved kidney function, morphological changes, and alterations of mRNA expression in the renal cortex, although late untreated controls did not show any improvement.


CONCLUSIONS
These results suggest that Rho-kinase inhibition partly reverses hypertensive glomerulosclerosis. The renoprotective effect of the Rho-kinase inhibitor may have multiple mechanisms including inhibition of extracellular matrix production, oxidative stress, adhesion molecule production, and antifibrinolysis.
Koshikawa
Shogo
S
Department of Hypertension and Cardiorenal Medicine, Dokkyo Medical University, Mibu, Tochigi, Japan.
Nishikimi
Toshio
T
Inaba
Chikako
C
Akimoto
Kazumi
K
Matsuoka
Hiroaki
H
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D024042:Collagen Type I / Q000235:genetics; D024061:Collagen Type III / Q000235:genetics; D004347:Drug Interactions; D004791:Enzyme Inhibitors / Q000633:toxicity; D006977:Hypertension, Renal / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018799:Intercellular Adhesion Molecule-1 / Q000235:genetics; D007668:Kidney / Q000187:drug effects / Q000201:enzymology; D008297:Male; D019255:NADPH Oxidases / Q000235:genetics; D019331:NG-Nitroarginine Methyl Ester / Q000633:toxicity; D009400:Nephrosclerosis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D052247:Nitric Oxide Synthase Type II / Q000235:genetics; D052250:Nitric Oxide Synthase Type III; D018384:Oxidative Stress / Q000187:drug effects; D017395:Plasminogen Activator Inhibitor 1 / Q000235:genetics; D047428:Protein Kinase Inhibitors / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011918:Rats, Inbred SHR; D013481:Superoxides / Q000378:metabolism; D016212:Transforming Growth Factor beta / Q000235:genetics; D054460:rho-Associated Kinases / Q000037:antagonists & inhibitors*; D020742:rhoA GTP-Binding Protein / Q000235:genetics; D020743:rhoB GTP-Binding Protein / Q000235:genetics
D024042:Collagen Type I; D024061:Collagen Type III; D004791:Enzyme Inhibitors; D017395:Plasminogen Activator Inhibitor 1; D047428:Protein Kinase Inhibitors; D012333:RNA, Messenger; D016212:Transforming Growth Factor beta; D013481:Superoxides; D018799:Intercellular Adhesion Molecule-1; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D052247:Nitric Oxide Synthase Type II; D052250:Nitric Oxide Synthase Type III; C496316:Nos3 protein, rat; D019255:NADPH Oxidases; D054460:rho-Associated Kinases; D020742:rhoA GTP-Binding Protein; D020743:rhoB GTP-Binding Protein; C049347:fasudil; D019331:NG-Nitroarginine Methyl Ester