Effects of asymmetric dimethylarginine on renal arteries in portal hypertension and cirrhosis

Figure 1 Effects of portal hypertension and cirrhosis on contractile effects induced by high extracellular concentrations of KCl in rat renal arteries. PPVL: Pre-hepatic portal hypertension; BDL: Bile duct ligation.

Figure 2 Effects of nitric oxide synthase inhibitors on basal nitric oxide release in renal artery. Contractions induced by L-NAME (n = 8) and ADMA (n = 8) on rings of rat renal artery with endothelium from Sham, PPVL, and BDL groups in the absence and in the presence of L-arginine (L-arg, 10^-3 mol/L, n = 6). Contractions were determined after evoking submaximal tone with 10^-7-3 × 10^-7 mol/L norepinephrine. PPVL: Pre-hepatic portal hypertension; BDL: Bile duct ligation; ADMA: Asymmetric dimethylarginine; L-NAME: N^G-nitro-L-arginine methyl ester.

Figure 3 Effects of nitric oxide synthase inhibitors on acetylcholine-induced relaxation in renal artery. A: Concentration-response curves to acetylcholine on rings of rat renal artery from Sham, PPVL, and BDL groups in artery rings with endothelium (n = 8) and without endothelium (n = 6) and in artery rings with endothelium in the presence of L-NAME (3 × 10^-4 mol/L; n = 8) or ADMA (3 × 10^-4 mol/L; n = 8). Relaxation is expressed as a percentage of the contraction in response to norepinephrine; B: Difference between the areas under curves (AUCs) from artery rings with endothelium (Control) and treated with L-NAME or ADMA. ^aP < 0.05 vs L-NAME treated group and ^cP < 0.05 vs Sham and PPVL groups treated with ADMA. PPVL: Pre-hepatic portal hypertension; BDL: Bile duct ligation.

Figure 4 DDAH1 and DDAH2 expression in kidneys from portal hypertensive and cirrhotic rats. A and B: DDAH1 and DDAH2 mRNA expression in kidney from Sham, PPVL, and BDL groups normalized to the expression of GAPDH, which was used as an endogenous reference gene; C and D: Immunoblot analysis in single kidney probed with antibodies against DDAH1, DDAH2 or β-actin, as indicated; E and F: Graphs show the results of densitometric analyses from pooled data, plotted as optical densitometry relative to the signal obtained by β-actin. Each data set represents the mean ± SEM derived from 6 independent experiments. ^aP < 0.05 vs Sham group and ^cP < 0.05 vs PPVL group. DDAH: Dimethylarginine dimethylaminohydrolase.

Figure 5 Effects of portal hypertension and cirrhosis on renal dimethylarginine dimethylaminohydrolase activity. Bar graphs represent DDAH activity in kidney from Sham, PPVL, and BDL groups. Each data set represents the mean ± SEM derived from 6 independent experiments. ^aP < 0.05 vs Sham group and ^cP < 0.05 vs PPVL group. DDAH: Dimethylarginine dimethylaminohydrolase.