Effect of Hepatic Artery Spasm on a Rat Model of Hepatic Ischemia-Reperfusion Injury.

Abstract

To investigate hemodynamic changes in the hepatic artery after hepatic ischemia-reperfusion injury (IRI) in rats via ultrasound (US) imaging and to discuss the protective effect of phentolamine (PHT) pretreatment on hepatic IRI. Fifty rats were randomly divided into 3 groups: a sham operation group (n = 10), a control ischemia-reperfusion group (n = 20), and a PHT pretreatment group (n = 20). Color Doppler flow imaging and contrast-enhanced US examinations were performed in each group at 30 minutes (n = 10) and 90 minutes (n = 10) after reperfusion. Blood samples were obtained to analyze serum alanine aminotransferase and aspartate aminotransferase levels, and liver tissue specimens were collected for pathologic analysis. Using US, we found that hepatic artery resistance at 30 minutes after reperfusion in the control group was higher than that in the sham group (mean resistive index [RI] ± SD, 0.65 ± 0.09 versus 0.50 ± 0.09; P < .01), which was higher at 30 than 90 minutes (RI, 0.65 ± 0.09 versus 0.50 ± 0.08; P < .01) after reperfusion in the control group. However, the hepatic artery resistance and liver microcirculation in the PHT group were better than those in the control group at 30 minutes after reperfusion (RI, 0.54 ± 0.09 versus 0.65 ± 0.09; P < .05; time to peak, 31.94 ± 2.02 versus 48.34 ± 4.74 seconds; P < .01). Compared to the control group, the aspartate aminotransferase and alanine aminotransferase levels were significantly lower at 30 minutes after reperfusion in the PHT group (P < .05). A pathologic examination revealed a smaller hepatic artery diameter and a depressed vessel wall in the control group. The hepatic artery can undergo a transient spasm during the hepatic IRI process, which can exacerbate liver damage. Phentolamine treatment can alleviate hepatic artery spasms, improve liver perfusion, and reduce liver injury by ameliorating the hepatic microcirculation.