BACKGROUND: Splanchnic vasodilation triggers the development of the hyperdynamic circulatory syndrome in portal hypertension. Neuropeptide Y (NPY), a sympathetic co-transmitter of norepinephrine, improves contractility in mesenteric arteries of pre-hepatic portal hypertensive rats. Therefore, we investigated the effect of NPY on mesenteric arterial contractility in vitro and in vivo in cirrhotic ascitic rats, as well as the vasoactive pathways involved. METHODS: All experiments were performed in CCl₄-induced cirrhotic rats with ascites and compared to controls. In vivo haemodynamic characterisation was assessed before and after cumulative application of NPY i.v. using the microspheres technique. In vitro mesenteric arterial perfusion was used to analyse the effect of NPY on the response to α₁-adrenergic, as well as nitrergic stimulation. The NPY effects on vasoactive pathways (RhoA/Rho-kinase and NOS/NO) were analysed by western blot in mesenteric arteries. RESULTS: NPY decreased portal-venous blood flow and reduced portal pressure in cirrhotic rats, without changes in mean arterial pressure. This was accompanied by decreased cardiac output and normalised systemic vascular resistance in cirrhotic rats. By contrast, no significant splanchnic or systemic haemodynamic effect of NPY was seen in controls. NPY enhanced arterial contractility in cirrhotic but not in control rats. Furthermore, NO-mediated vasodilation was reduced to a greater extent than in controls. These findings were paralleled by an increased expression and activity of the constrictive Rho-kinase pathway and decreased activation of vasodilating NOS/NO signalling after NPY administration in mesenteric arteries. CONCLUSIONS: NPY exerts marked portal hypotensive effects and ameliorates the hyperdynamic circulation in cirrhotic ascitic rats. This is mediated mainly by a pronounced splanchnic vasoconstriction and reduction in splanchnic blood flow due to enhanced Rho-kinase expression and activity, as well as reduced NOS activation and NO effect.
BACKGROUND: Splanchnic vasodilation triggers the development of the hyperdynamic circulatory syndrome in portal hypertension. Neuropeptide Y (NPY), a sympathetic co-transmitter of norepinephrine, improves contractility in mesenteric arteries of pre-hepatic portal hypertensiverats. Therefore, we investigated the effect of NPY on mesenteric arterial contractility in vitro and in vivo in cirrhotic asciticrats, as well as the vasoactive pathways involved. METHODS: All experiments were performed in CCl₄-induced cirrhotic rats with ascites and compared to controls. In vivo haemodynamic characterisation was assessed before and after cumulative application of NPY i.v. using the microspheres technique. In vitro mesenteric arterial perfusion was used to analyse the effect of NPY on the response to α₁-adrenergic, as well as nitrergic stimulation. The NPY effects on vasoactive pathways (RhoA/Rho-kinase and NOS/NO) were analysed by western blot in mesenteric arteries. RESULTS:NPY decreased portal-venous blood flow and reduced portal pressure in cirrhotic rats, without changes in mean arterial pressure. This was accompanied by decreased cardiac output and normalised systemic vascular resistance in cirrhotic rats. By contrast, no significant splanchnic or systemic haemodynamic effect of NPY was seen in controls. NPY enhanced arterial contractility in cirrhotic but not in control rats. Furthermore, NO-mediated vasodilation was reduced to a greater extent than in controls. These findings were paralleled by an increased expression and activity of the constrictive Rho-kinase pathway and decreased activation of vasodilating NOS/NO signalling after NPY administration in mesenteric arteries. CONCLUSIONS:NPY exerts marked portal hypotensive effects and ameliorates the hyperdynamic circulation in cirrhotic asciticrats. This is mediated mainly by a pronounced splanchnic vasoconstriction and reduction in splanchnic blood flow due to enhanced Rho-kinase expression and activity, as well as reduced NOS activation and NO effect.
Authors: Peter Dietrich; Laura Wormser; Valerie Fritz; Tatjana Seitz; Monica De Maria; Alexandra Schambony; Andreas E Kremer; Claudia Günther; Timo Itzel; Wolfgang E Thasler; Andreas Teufel; Jonel Trebicka; Arndt Hartmann; Markus F Neurath; Stephan von Hörsten; Anja K Bosserhoff; Claus Hellerbrand Journal: J Clin Invest Date: 2020-05-01 Impact factor: 14.808
Authors: Sabine Klein; Christian Hinüber; Kanishka Hittatiya; Robert Schierwagen; Frank Erhard Uschner; Christian P Strassburg; Hans-Peter Fischer; Ulrich Spengler; Jonel Trebicka Journal: PLoS One Date: 2016-09-02 Impact factor: 3.240
Authors: Christian Liedtke; Tom Luedde; Tilman Sauerbruch; David Scholten; Konrad Streetz; Frank Tacke; René Tolba; Christian Trautwein; Jonel Trebicka; Ralf Weiskirchen Journal: Fibrogenesis Tissue Repair Date: 2013-10-01