HEMODYNAMIC-EFFECTS OF CHRONIC OCTREOTIDE AND TETRANDRINE ADMINISTRATION IN PORTAL HYPERTENSIVE RATS

Octreotide is an effective portal hypotensive drug in the control of v ariceal bleeding. Tetrandrine is a type of calcium channel blocker rec ently reported to reduce portal hypertension. The present study was un dertaken to investigate the haemodynamic effects of octreotide and tet randrine, alone and in combination, in portal hypertensive rats. Porta l hypertension was induced by partial portal vein ligation. Portal hyp ertensive rats were allocated into one of the four groups: vehicle gro up (saline, 0.5 mL/day), octreotide group (100 mu g/kg per 12h), tetra ndrine group (20mg/kg per 12h), and octreotide (100 mu g/kg per 12 h) plus tetrandrine (20 mg/kg per 12 h) group. Tetrandrine or saline was administered by gavage, and octreotide by subcutaneous injection. The drug was given for 8 consecutive days, starting 1 day before ligation and continuing onwards. Haemodynamic parameters were measured thereaft er, using the radioactive microsphere method. The portal venous pressu re and portal tributary blood flow were significantly reduced, while p ortal territory and renal vascular resistances were significantly enha nced, by octreotide, tetrandrine, or octreotide plus tetrandrine in po rtal hypertensive rats, compared with the vehicle group. Our results s howed that long-term administration of octreotide, tetrandrine, or oct reotide plus tetrandrine led to portal hypotensive effects in portal h ypertensive rats, but octreotide alone exerted better anti-hyperdynami c effects compared with tetrandrine alone. A combination of octreotide and tetrandrine offered no major beneficial anti-hyperdynamic effects compared with octreotide alone.