Portosystemic collaterals in cirrhosis are often complicated with hemorrhage. Endothelin-1 (ET-1) and argi-nine vasopressin (AVP) have been shown to directly constrict collaterals of portal hypertensive rats. Furthermore, octreotide, a long-acting somatostatin analog, enhances ET-1-related collateral vasoconstriction if administered in the perfusate before ET-1 incubation. However, long-term effects of somatostatin analogs on collateral response to ET-1 and AVP remain unclarified. This study investigated the effects of lanreotide (a longer-acting somatostatin analog when compared with octreotide) on the portosystemic collateral vascular reactiveness to ET-1 and AVP in cirrhotic rats.
Liver cirrhosis was induced in Sprague-Dawley rats by common bile duct ligation (BDL). On the 33rd day after BDL, rats received 1 intramuscular injection with lanreotide (10 mg/kg) or distilled water. On the 43rd day after BDL, systemic, and portal hemodynamics were evaluated. By an in situ perfusion model, ET-1 (10−10 −10−7 mol/L) and AVP (10−10 −3 × 10−7 mol/L) were applied to assess the collateral responses.
Heart rate, mean arterial pressure, and portal pressure were not modified by lanreotide. Lanreotide pretreat-ment enhanced collateral vascular response to ET-1 and reached statistical significance at 10−7 mol/L without inducing changes to AVP.
Lanreotide augmented the collateral vascular responsiveness to ET-1 but not to AVP in cirrhotic rats.