Heat shock protein 90 is responsible for hyperdynamic circulation in portal hypertensive rats

AIM: To examine the participation of HSP90 in portal hypertensive rat mesentery in vitro.METHODS: Immunohistochemistry and Western-blot were used to examine the expression of HSP90 in mesenteric vasculature. HSP90 mRNA was detected by RT-PCR, and the role of HSP90 in hyperdynamic circulation was examined by in vitro mesenteric perfusion studies.RESULTS: HSP90 was overexpressed in endothelium of mesentery vasculature in animals with experimental portal hypertension induced by partial portal vein ligation (PVL) compared with normal animals. Geldanamycin (GA), a special inhibitor of HsPg0 signaling, attenuated ACh-dependent vasodilation but did not affect vasodilation in response to sodium nitroprusside in normal rats. In PVL animals, the perfused mesentery was hyporesponsive to vasoconstrictor methoxamine. GA significantly potentiated methoxamineinduced vasoconstrictor after PVL.CONCLUSION: HsPg0 plays a key role in NO-dependent hyperdynamic circulation in portal hypertension and provides a novel method for future treatment of portal hypertension.

Expression of local renin and angiotensinogen mRNA in cirrhotic portal hypertensive patient

AIM: To investigate the expression of local renin and angiotensinogen mRNA in cirrhotic portal hypertensive patients.METHODS: The expression of local renin and angiotensinogen mRNA in the liver, splenic artery and vein of PH patients was detected by RT-PCR analysis.RESULTS: Expression of local renin mRNA in the liver of control group was (0.19±0.11), significantly lower than that in splenic artery(0.45±0.17)or splenic vein(0.39±0.12)respectively, (P＜0.05). Expression of local angiotensinogen mRNA in the liver was (0.64±0.21), significantly higher than that in splenic artery(0.41±0.15) or in splenic vein (0.35±0.18)respectively, (P＜0.05). Expression of local renin mRNA in the liver, splenic artery and vein of PH group was (0.78±0.28),(0.86±0.35) and (0.81±0.22) respectively, significantly higher than that in the control group, (P＜0.05). Expression of local angiotensinogen mRNA in the liver, splenic artery and vein of PH group was (0.96±0.25), (0.83±0.18) and (0.79±0.23)respectively, significantly higher than that in the control group,(P＜0.05). There was no significant difference between the liver, splenic artery and vein in the expression of local renin or local angiotensinogen mRNA in PH group, (P＜0.05).CONCLUSION: In normal subjects the expression of local renin and angiotensinogen mRNA was organ specific, but with increase of the expression of LRAS, the organ-specificity became lost in cirrhotic patients. LRAS may contribute to increased resistance of portal vein with liver and formation of splanchnic vasculopathy.