Inhibition of Inducible Nitric Oxide Synthase Prevents Hepatic, but Not Pulmonary, Injury Following Ischemia-Reperfusion of Rat Liver

2006 ◽  
Vol 51 (3) ◽  
pp. 571-579 ◽  
Author(s):  
Yuji Takamatsu ◽  
Kazuo Shimada ◽  
Koji Yamaguchi ◽  
Syoji Kuroki ◽  
Kazuo Chijiiwa ◽  
...  
2021 ◽  
pp. 096032712199944
Author(s):  
Mohamed IA Hassan ◽  
Fares EM Ali ◽  
Abdel-Gawad S Shalkami

Aim: Hepatic ischemia/reperfusion (I/R) injury is a syndrome involved in allograft dysfunction. This work aimed to elucidate carvedilol (CAR) role in hepatic I/R injury. Methods: Male rats were allocated to Sham group, CAR group, I/R group and CAR plus I/R group. Rats subjected to hepatic ischemia for 30 minutes then reperfused for 60 minutes. Oxidative stress markers, inflammatory cytokines and nitric oxide synthases were measured in hepatic tissues. Results: Hepatocyte injury following I/R was confirmed by a marked increase in liver enzymes. Also, hepatic I/R increased the contents of malondialdehyde however decreased glutathione contents and activities of antioxidant enzymes. Furthermore, hepatic I/R caused elevation of toll-like receptor-4 (TLR-4) expression and inflammatory mediators levels such as tumor necrosis factor-α, interleukin-6 and cyclooxygenase-II. Hepatic I/R caused down-regulation of endothelial nitric oxide synthase and upregulation of inducible nitric oxide synthase expressions. CAR treatment before hepatic I/R resulted in the restoration of liver enzymes. Administration of CAR caused a significant correction of oxidative stress and inflammation markers as well as modulates the expression of endothelial and inducible nitric oxide synthase. Conclusions: CAR protects liver from I/R injury through reduction of the oxidative stress and inflammation, and modulates endothelial and inducible nitric oxide synthase expressions.


1999 ◽  
Vol 19 (6) ◽  
pp. 667-672 ◽  
Author(s):  
Shunya Takizawa ◽  
Naoto Fukuyama ◽  
Hisayuki Hirabayashi ◽  
Hiroe Nakazawa ◽  
Yukito Shinohara

The purpose of this study was to establish the dynamics of nitrotyrosine (NO2-Tyr) formation and decay during the rise of NO2-Tyr in rat brain subjected to 2-hour focal ischemia-reperfusion, and to evaluate the role of inducible nitric oxide synthase in the rise. The authors first determined the half life of NO2-Tyr in rat brain at 24 hours after the start of reperfusion by blocking NO2-Tyr formation with NG-monomethyl-l-arginine and after the decay of NO2-Tyr by means of a hydrolysis/HPLC procedure. The values obtained were approximately 2 hours in both peri-infarct and core-of-infarct regions. Using the same hydrolysis/HPLC procedure, the ratio of nitrotyrosine to tyrosine from the 2-hour occlusion to as much as 72 hours after the start of reperfusion was measured in the presence and absence of aminoguanidine (100 mg/kg intraperitoneally twice a day). In the absence of aminoguanidine, the ratio of NO2-Tyr in the peri-infarct and core-of-infarct regions reached 0.95% ± 0.34% and 0.52% ± 0.34%, respectively, at 1 hour after the start of reperfusion, The elevated levels persisted until 48 hours, then declined, The peri-infarct region showed the highest percent NO2-Tyr level, followed by the core of infarct, then the caudoputamen, Aminoguanidine significantly reduced NO2-Tyr formation (up to 90% inhibition) during 24 to 48 hours, The authors conclude that inducible nitric oxide synthase is predominantly responsible for NO2-Tyr formation, at least in the late phase of reperfusion, These results have important implications for the therapeutic time window and choice of nitric oxide synthase inhibitors in patients with cerebral infarction.


2002 ◽  
Vol 61 (3) ◽  
pp. 862-871 ◽  
Author(s):  
Prabal K. Chatterjee ◽  
Nimesh S.A. Patel ◽  
Espen O. Kvale ◽  
Salvatore Cuzzocrea ◽  
Paul A.J. Brown ◽  
...  

2004 ◽  
Vol 287 (5) ◽  
pp. G1008-G1016 ◽  
Author(s):  
Marieke G. L. Elferink ◽  
Peter Olinga ◽  
Annelies L. Draaisma ◽  
Marjolijn T. Merema ◽  
Klaas Nico Faber ◽  
...  

Endotoxin-induced cholestasis in rodents is caused by hepatic downregulation of transporters, including the basolateral Na+-dependent taurocholate transporter (ntcp) and the canalicular bile salt export pump (bsep) and multidrug resistance-associated protein 2 (mrp2). Details about the regulation of the human transporter proteins during this process are lacking. We used precision-cut human and rat liver slices to study the regulation of transporter expression during LPS-induced cholestasis. We investigated the effect of LPS on nitrate/nitrite and cytokine production in relation to the expression of inducible nitric oxide synthase, NTCP, BSEP, and MRP2 both at the level of mRNA with RT-PCR and protein using immunofluorescence microscopy. In liver slices from both species, LPS-induced expression of inducible nitric oxide synthase was detected within 1–3 h and remained increased over 24 h. In rat liver slices, this was accompanied by a significant decrease of rat ntcp and mrp2 mRNA levels, whereas bsep levels were not affected. These results are in line with previous in vivo studies and validate our liver slice technique. In LPS-treated human liver slices, NTCP mRNA was downregulated and showed an inverse correlation with the amounts of TNF-α and Il-1β produced. In contrast, MRP2 and BSEP mRNA levels were not affected under these conditions. However, after 24-h LPS challenge, both proteins were virtually absent in human liver slices, whereas marker proteins remained detectable. In conclusion, we show that posttranscriptional mechanisms play a more prominent role in LPS-induced regulation of human MRP2 and BSEP compared with the rat transporter proteins.


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