Octreotide is an effective portal hypotensive
drug in the control of variceal
bleeding.
Tetrandrine is a type of
calcium channel blocker recently reported to reduce
portal hypertension. The present study was undertaken to investigate the haemodynamic effects of
octreotide and
tetrandrine, alone and in combination, in portal hypertensive rats.
Portal hypertension was induced by partial portal vein
ligation. Portal hypertensive rats were allocated into one of the four groups: vehicle group (saline, 0.5 mL/day),
octreotide group (100 microg/kg per 12 h),
tetrandrine group (20 mg/kg per 12 h), and
octreotide (100 microg/kg per 12 h) plus
tetrandrine (20mg/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 thereafter, using the radioactive
microsphere method. The portal venous pressure and portal tributary blood flow were significantly reduced, while portal territory and renal vascular resistances were significantly enhanced, by
octreotide,
tetrandrine, or
octreotide plus
tetrandrine in portal hypertensive rats, compared with the vehicle group. Our results showed that long-term administration of
octreotide,
tetrandrine, or
octreotide plus
tetrandrine led to portal hypotensive effects in portal hypertensive rats, but
octreotide alone exerted better anti-hyperdynamic effects compared with
tetrandrine alone. A combination of
octreotide and
tetrandrine offered no major beneficial anti-hyperdynamic effects compared with
octreotide alone.