Experimental study on α1 adrenergic receptor blocker in reducing portal hypertension in rats / 中华消化杂志

ABSTRACT

Objective:To observe whether α1 adrenergic receptor (α1AR) blocker can reduce and antagonize portal hypertension caused by α1AR activation in rats, and to provide a new approach for the clinical treatment of portal hypertension.Methods:Phenylephrine was chosen as α1AR agonist, and alfuzosin was used as α1AR blocker. The route of administration was portal vein injection, and the pressure was measured by trans-portal vein puncture. According to random number table, 32 male Sprague-Dawley rats were divided into 4 groups control group, portal hypertension model group, alfuzosin treatment group and alfuzosin prevention group. The portal venous pressure (PVP) was measured in all rats before administration. The rats in the control group were injected with 0.9% sodium chloride solution (1 L/g), and the rats in portal hypertension model group were injected with phenylephrine(1.5 μg/g), and the PVP of the above two groups was measured again at 5 and 10 min after injection. The rats in alfuzosin treatment group were injected with phenylephrine(1.5 μg/g), PVP was measured again at 5 min after administration, and then the rats were given alfuzosin(0.9 μg/g), PVP was measured again at 5 min after administration. The rats in alfuzosin prevention group were injected with alfuzosin(0.9 μg/g), PVP was measured at 1 min after administration, and then the rats were given phenylephrine(1.5 μg/g), PVP was measured again at 1, 5 and 10 min after phenylephrine injection respectively. One way analysis of variance and Dunnett- t test were used for statistical analysis. Results:The portal vein puncture was successfully performed in 4, 6, 8 and 5 rats in the control group, portal hypertension model group, alfuzosin treatment group and alfuzosin prevention group, respectively. The PVP of rats in portal hypertension model group at 5 and 10 min after phenylephrine injection was (18.045±7.636) and (15.515±5.440) mmHg (1 mmHg = 0.133 kPa), respectively, which were both higher than that before administration ((8.452±2.830) mmHg), and the differences were statistically significant ( t=2.89 and 2.82, both P<0.05). At 5 min after alfuzosin injection, the PVP of rats in the alfuzosin treatment group was (10.088±3.743) mmHg, which was lower than that of rats at 5 min after phenylephrine injection ((16.146±4.324) mmHg) and that of portal hypertension model group at 10 min after phenylephrine injection, and the differences were statistically significant ( t=3.00 and 2.22, both P<0.05). There were no significant differences in PVP in the alfuzosin prevention group before administration, at 1 min after injection of alfuzosin, and at 1, 5 and 10 min after injection of phenylephrine (all P > 0.05). Conclusions:α1AR is an important factor involved in the regulation of PVP, and its blockers can reduce and antagonize the portal hypertension caused by α1AR activation, which is of great significance in the prevention and treatment of portal hypertension progression in liver cirrhosis.