Hepatic and Plasma Endothelin-1 in Dogs with Chronic Hepatitis

Background: Endothelin (ET)-1 is a 21-amino-acid peptide with potent vasoactive properties, which increases intrahepatic resistance in patients with chronic hepatitis (CH) or cirrhosis. ET-1 concentrations have not been investigated in dogs with CH. Hypothesis/Objectives: This study compared hepatic and plasma ET-1 levels in healthy dogs and in dogs with CH, and examined the relationship between the plasma ET-1 level and portal vein pressure in dogs with CH. Animals: Fourteen healthy dogs and twenty dogs with CH were used in this study. Methods: Prospective case-control study. Hepatic ET-1 mRNA expression was determined by real-time reverse transcription polymerase chain reaction, and hepatic and plasma ET-1 levels were assessed using ELISA. Splenic pulp pressure (SPP), as an indicator of portal vein pressure, was measured laparoscopically. Results: Hepatic ET-1 mRNA levels were 3.7 times higher in dogs with CH than in healthy dogs (P =.008). The median hepatic and plasma ET-1 protein levels were significantly higher in dogs with CH than in healthy dogs (13.20 pg/mg wet liver vs. 3.42 pg/mg wet liver, P =.004, and 0.99 pg/mL vs. 0.71 pg/mL, P =.013, respectively). Moreover, there was a weak but significant correlation between plasma ET-1 level and SPP in dogs with CH (P =.036; r_s = 0.53). Conclusions and clinical importance: The results indicate that ET-1 might play an important role in the pathogenesis of portal hypertension caused by CH.