Haemodynamic effects of chronic tetrandrine treatment in portal hypertensive rats

Tetrandrine is a calcium channel antagonist with reported antihypertensive effect. However, the potential role of tetrandrine as a therapeutic agent in portal hypertension has yet to be explored. The present study aimed to investigate the haemodynamic effects of chronic tetrandrine treatment on portal hypertensive rats. Portal hypertension was induced by partial portal vein ligation in Sprague-Dawley rats. Animals were allocated into one of two groups: a tetrandrine group and a vehicle group. Tetrandrine (20 mg/kg) or vehicle was administered by gavage every 12 h for 8 consecutive days, starting 1 day before ligation and continuing thereafter. After 8 days of tetrandrine treatment, systemic haemodynamics, organ blood flows and the degree of portal-systemic shunting were measured after an overnight fast. The portal venous pressure and portal tributary blood flow were significantly decreased, while portal territory as well as hepato-collateral vascular resistance significantly increased in the tetrandrine group compared with the vehicle group. The cardiac index was increased, while systemic vascular resistance was decreased, in the tetrandrine group. Mean arterial pressure, heart rate, portalsystemic shunting and bodyweight were similar between the two groups. Renal blood flow was decreased in the tetrandrine group. In conclusion, long-term treatment of tetrandrine reduced portal venous pressure and alleviated splanchnic hyperaemia in portal hypertensive rats without affecting the portal-systemic shunting.