scholarly journals The Impact of a Nitric Oxide Synthase Inhibitor (L-NAME) on Ischemia–Reperfusion Injury of Cholestatic Livers by Pringle Maneuver and Liver Resection after Bile Duct Ligation in Rats

2019 ◽  
Vol 20 (9) ◽  
pp. 2114 ◽  
Author(s):  
Junji Iwasaki ◽  
Mamdouh Afify ◽  
Christian Bleilevens ◽  
Uwe Klinge ◽  
Ralf Weiskirchen ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Liver Resection ◽  
Bile Duct ◽  
Bile Duct Ligation ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Pringle Maneuver ◽  
Endothelial Lining ◽  
Duct Ligation ◽  
Oxide Synthase

The Pringle maneuver (PM) has been widely used to control blood loss during liver resection. However, hepatic inflow occlusion can also result in hepatic ischemia–reperfusion injury (IRI), especially in patients with a cholestatic, fibrotic, or cirrhotic liver. Here we investigate a nitric oxide synthase (NOS) inhibitor N-Nitroarginine methyl ester (L-NAME) on IRI after the PM and partial hepatectomy of cholestatic livers induced by bile duct ligation (BDL) in rats. Control group (non-BDL/no treatment), BDL + T group (BDL/L-NAME treatment) and BDL group (BDL/no treatment) were analyzed. Cholestasis was induced by BDL in the L-NAME and BDL group and a 50% partial hepatectomy with PM was performed. L-NAME was injected before PM in the BDL + T group. Hepatocellular damage, portal venous flow, microcirculation, endothelial lining, and eNOS, iNOS, interleukin (IL)-6, and transforming growth factor-β (TGF-β) were evaluated. Microcirculation of the liver in the BDL + T group tended to be higher. Liver damage and apoptotic index were significantly lower and Ki-67 labeling index was higher in the BDL + T group while iNOS and TGF-β expression was decreased. This was corroborated by a better preserved endothelial lining. L-NAME attenuated IRI following PM and improved proliferation/regeneration of cholestatic livers. These positive effects were considered as the result of improved hepatic microcirculation, prevention of iNOS formation, and TGF-β mRNA upregulation.

Effects of chronic nitric oxide activation or inhibition on early hepatic fibrosis in rats with bile duct ligation

1999 ◽  
Vol 96 (3) ◽  
pp. 297-305 ◽  
Author(s):  
Paula MAYORAL ◽  
Manuela CRIADO ◽  
Froilan HIDALGO ◽  
Olga FLORES ◽  
Miguel A. ARÉVALO ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Bile Duct ◽  
Nitric Oxide Synthase ◽  
Hepatic Fibrosis ◽  
Bile Duct Ligation ◽  
Common Bile Duct Ligation ◽  
Western Blots ◽  
Circulatory Effects ◽  
Duct Ligation ◽  
Oxide Synthase

Hepatic fibrosis or increased liver collagen contents drive functional abnormalities that, when extensive, may be life threatening. The purpose of this study was to assess the effects of the chronic stimulation or inhibition of nitric oxide synthesis in rats with hepatic fibrosis induced by permanent common bile duct ligation (3 weeks) and the role of expression of the different nitric oxide synthase isoforms. Bile duct ligation led to an important accumulation of collagen in the hepatic parenchyma, as shown both histologically and by the hydroxyproline contents of livers. Bilirubin and serum enzyme activities (measured as markers of cholestasis) increased several-fold after bile duct ligation. The area of fibrotic tissue, liver hydroxyproline content and serum markers of cholestasis were clearly related in obstructed rats. The absence of modifications in haemodynamic parameters excludes circulatory changes from being responsible for the development of liver alterations. In animals treated with NG-nitro-L-arginine methyl ester (L-NAME) the area of fibrosis was similar to that of untreated animals, the signs of cholestasis and cellular injury being more evident. In rats treated with L-arginine the area of fibrosis was almost three times larger than that found in bile duct ligated rats and in L-NAME-treated bile duct ligated rats, although the observed biochemical changes were similar to those seen in rats treated with L-NAME. Our results with inducible nitric oxide synthase, obtained by Western blots and immunohistochemistry, indicate a greater expression of the inducible enzyme in bile duct ligated and L-arginine-treated animals and a lower expression in the L-NAME and control groups. Constitutive nitric oxide synthase expression, obtained by Western blots, was very similar in all groups, except for the L-arginine-treated rats in which it was lower. These results suggest that nitric oxide production may be a key factor in the development of fibrosis in bile duct ligated rats. They also support the hypothesis of a dual role for nitric oxide; one beneficial, mediated by its circulatory effects, and the second negative, through its local toxic effects.

Interaction between prostanoids and nitric oxide in the control of tubular function in rats with chronic bile duct ligation

1999 ◽  
Vol 77 (2) ◽  
pp. 111-117 ◽  
Author(s):  
Manuela Criado ◽  
Olga Flores ◽  
Froilán Hidalgo ◽  
José M López-Novoa ◽  
Angel Sánchez-Rodríguez
Keyword(s):  
Nitric Oxide ◽  
Mean Arterial Pressure ◽  
Bile Duct ◽  
Methyl Ester ◽  
Arterial Pressure ◽  
Bile Duct Ligation ◽  
Prostaglandin E ◽  
Duct Ligation ◽  
Pressure Natriuresis ◽  
Oxide Synthase

Recent work indicates that both nitric oxide and cyclooxygenase products play an important role in the renal alterations of liver cirrhosis, although the interactions between them have not been completely established. The purpose of this study was to assess the effect of simultaneous blockade of nitric oxide synthase and cyclooxygenase in rats with chronic bile duct ligation and in control, sham-operated rats. Compared with control rats, chronic bile duct ligation rats, 23-25 days after surgery, showed a decreased mean arterial pressure, natriuresis, and kaliuresis, without differences in glomerular filtration rate, and an increased urinary nitrite excretion. Nitric oxide synthesis inhibition by administration of NG-nitro-L-arginine methyl ester induced, in control rats, an increase in mean arterial pressure, without significant changes in natriuresis or glomerular filtration rate. In chronic bile duct ligation rats, NG-nitro-L-arginine methyl ester induced an increase in mean arterial pressure, natriuresis, and kaliuresis, together with a reduction in urinary nitrite excretion and an increase in prostaglandin E2 excretion. Cyclooxygenase inhibition with indomethacin induced in both experimental groups a marked inhibition in urinary prostaglandin E2 excretion without significant changes in Na+ or K+ excretion, and a significant increase in urinary nitrite excretion in control rats. NG-Nitro-L-arginine methyl ester in addition to indomethacin prevented the indomethacin-induced increase in nitrite excretion and dramatically reduced sodium excretion in both experimental groups. Thus, the present study suggests that both nitric oxide and cyclooxygenase products interact in the control of urinary sodium excretion and that each system is activated in the absence of the other one.Key words: kidney, biliary cirrhosis, nitric oxide synthase, cyclooxygenase.

Tackling endothelial dysfunction by modulating NOS uncoupling: new insights into its pathogenesis and therapeutic possibilities

2012 ◽  
Vol 302 (5) ◽  
pp. E481-E495 ◽  
Author(s):  
Rinrada Kietadisorn ◽  
Rio P. Juni ◽  
An L. Moens
Keyword(s):  
Nitric Oxide ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Therapeutic Interventions ◽  
Enos Uncoupling ◽  
Underlying Causes ◽  
Oxide Synthase ◽  
Endothelial Nitric Oxide

Endothelial nitric oxide synthase (eNOS) serves as a critical enzyme in maintaining vascular pressure by producing nitric oxide (NO); hence, it has a crucial role in the regulation of endothelial function. The bioavailability of eNOS-derived NO is crucial for this function and might be affected at multiple levels. Uncoupling of eNOS, with subsequently less NO and more superoxide generation, is one of the major underlying causes of endothelial dysfunction found in atherosclerosis, diabetes, hypertension, cigarette smoking, hyperhomocysteinemia, and ischemia/reperfusion injury. Therefore, modulating eNOS uncoupling by stabilizing eNOS activity, enhancing its substrate, cofactors, and transcription, and reversing uncoupled eNOS are attractive therapeutic approaches to improve endothelial function. This review provides an extensive overview of the important role of eNOS uncoupling in the pathogenesis of endothelial dysfunction and the potential therapeutic interventions to modulate eNOS for tackling endothelial dysfunction.

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