NO donor V-PYRRO/NO inhibits expression of leukotriene C4 synthase in early stage of hepatic ischemia/reperfusion injury in rats / 基础医学与临床

ABSTRACT

Objective To explore the mechanism underlying a selective liver nitric oxide donor V-PYRRO/NO effects on the gene expression of LTC4 synthase(LTC4S) during hepatic ischemia reperfusion(I/R).Methods Adult male SD rats were divided into 3 groupscontrol group(sham),ischemic-reperfusion group(I/R) and V-PYRRO/NO group. Liver subjected to 1 hour of partial hepatic ischemia followed by 5 hours of reperfusion, saline or V-PYRRO/NO[1.06 mmol/(kg·h)] administered intravenously. The mRNA expression of LTC4S in rat liver was examined by RT-PCR method,the protein expressions of NF-κB p65,p50 and IκB in liver cell lysates and nu-clear extracts were detected by Western blot analysis. Results Hepatic mRNA expression of LTC4S in I/R group was higher than that in sham group(P<0.05), whereas it was lower in V-PYRRO/NO group than that in I/R group(P<0.05). Moreover,compared with sham group,the protein expressions of NF-κB p65 and p50 in nucleus extract were markedly increased(P<0.01) but significantly decreased in cytoplasm(P<0.01) in I/R group. V-PYRRO/NO reversed completely the increase of these protein expressions in nucleus extract (P<0.05) and the decrease of them in cytoplasm(P<0.01,P<0.05) during hepatic I/R injury.However,IκB protein in three groups did not change. Immunohistochemistry staining revealed that no marked positive staining for NF-κB p65 was found in sham liver,I/R liver exhibited strong cytoplasmic and nuclear positive staining for NF-κB p65,but V-PYRRO/NO I/R group liver presented slight cytoplasmic and nuclear staining. Conclusions V-PYRRO/NO may down-regulate LTC4S mRNA expression by inhibiting NF-κB activation independent of IκB during hepatic I/R injury.