AIM： To investigate the in vivo effect of atrial natriuretic peptide （ANP） and its signaling pathway during orthotopic rat liver transplantation.METHODS： Rats were infused with NaCI, ANP （5 μg/ kg）, wortmannin ...AIM： To investigate the in vivo effect of atrial natriuretic peptide （ANP） and its signaling pathway during orthotopic rat liver transplantation.METHODS： Rats were infused with NaCI, ANP （5 μg/ kg）, wortmannin （WH, 16μg/kg）, or a combination of both for 20 min. Livers were stored in UW solution （4℃） for 24 h, transplanted and reperfused. Apoptosis was examined by caspase-3 activity and TUNEL staining. Phosphorylation of Akt and Bad was visualized by Western blotting and phospho-Akt-localization by confocal microscopy.RESULTS： ANP-pretreatment decreased caspase-3 activity and TUNELopositive cells after cold ischemia, indicating antiapoptotic effects of ANP in vivo. The an- tiapoptotic signaling of ANP was most likely caused by phosphorylation of Akt and Bad, since pretreatment with PI 3-kinase inhibitor WM abrogated the ANP-induced reduction of caspase-3 activity. Interestingly, analysis of liver tissue by confocal microscopy showed translocation of phosphorylated Akt to the plasma membrane of hepa- tocytes evoked by ANP.CONCLUSION： ANP activates the PI-3-kinase pathway in the liver in vivo leading to phosphorylation of Bad an event triggering antiapoptotic signaling cascade in ischemic liver.展开更多
基金Supported by the DFG(FOR 440/1)the Alexander von Humboldt Foundation(A.K.K).
文摘AIM： To investigate the in vivo effect of atrial natriuretic peptide （ANP） and its signaling pathway during orthotopic rat liver transplantation.METHODS： Rats were infused with NaCI, ANP （5 μg/ kg）, wortmannin （WH, 16μg/kg）, or a combination of both for 20 min. Livers were stored in UW solution （4℃） for 24 h, transplanted and reperfused. Apoptosis was examined by caspase-3 activity and TUNEL staining. Phosphorylation of Akt and Bad was visualized by Western blotting and phospho-Akt-localization by confocal microscopy.RESULTS： ANP-pretreatment decreased caspase-3 activity and TUNELopositive cells after cold ischemia, indicating antiapoptotic effects of ANP in vivo. The an- tiapoptotic signaling of ANP was most likely caused by phosphorylation of Akt and Bad, since pretreatment with PI 3-kinase inhibitor WM abrogated the ANP-induced reduction of caspase-3 activity. Interestingly, analysis of liver tissue by confocal microscopy showed translocation of phosphorylated Akt to the plasma membrane of hepa- tocytes evoked by ANP.CONCLUSION： ANP activates the PI-3-kinase pathway in the liver in vivo leading to phosphorylation of Bad an event triggering antiapoptotic signaling cascade in ischemic liver.
