Acute hemodynamic effects of tetramethylpyrazine and tetrandrine on cirrhotic rats

The hemodynamic effects of tetramethylpyrazine (TMP) and tetrandrine (TET), both alkaloids isolated from Chinese herbs Ligusticum wallichii Franch and Stephania tetrandra S. Moore, respectively, were assessed in anesthetized cirrhotic rats. TMP induced dose-dependent decreases of portal venous pressure (P.V.P.) and mean arterial pressure (M.A.P.) after intravenous infusion. The maximum percentage reduction of P.V.P. after TMP was 3.6 +/- 0.8%, 6.8 +/- 0.5%, and 17.8 +/- 0.6% of baseline, respectively, for the dosages given (3.0, 9.9 and 30.0 mg/kg). Similarly, TET induced dose-dependent decreases of P.V.P. and M.A.P. The maximum percentage reduction of P.V.P. after TET was 5.4 +/- 1.0%, 9.2 +/- 0.8%, and 23.7 +/- 1.2% of baseline, respectively, for the dosages given (2.0, 6.6 and 20.0 mg/kg). Total peripheral resistance was also reduced by TMP as well as TET. Our results showed that TMP and TET induced P.V.P. reduction in cirrhotic rats, together with reduction in M.A.P. and total peripheral resistance.