Endothelin A Receptor MRNA Expression In Liver During The Development Of Liver Cirrhosis In Rats

Objective: To observe endothelin A receptor mRNA expression in liver and discuss the regulation mechanism of endothelin and its receptor during the development of liver cirrhosis and portal hypertension (PHT) in Wistar rats.Methods: In s itu h ybridization of mRNA was used todelect the location and the quantity of endothelin A receptor in liver. 71 male Wistar rats were divided into four groups randomly: control group was 13, 1 month group (degeneration and necrosis period) 20, 2 month group (nodule regeneration period) 20, and 3 month group (false lobule period) 18. Liver cirrhosis and PUT was induced by subcutaneous injection of 60% tetrachloride (CCl4). The experiment have 4 main parts. The first, portal pressure and endothelin level in portal and peripheral blood was determined, and the relationship between them was discussed during the period of the formation of liver cirrhosis and PHT. The second, histological changes of liver were estimated, endothelin receptor mRNA of liver was examed by in situ hybridization after keeping in liquid nitrogen. The third, mRNA sequences of endothelin receptor A, B, C (ETA,ETB, ETC) of rats were analyzed and a 33 bp ETA probe was designed by "DNAstar" software, finally, ETA mRNA was analyzed by quantitative image analyzer.Result: l.Along with the formation of liver cirrhosis and PHT, special pathology changes occurred in liver: degeneration and necrosis of hepatocytes, tubercule hyperplasia, psendolobe formation; 2. portal pressure was elevated gradually; 3.peripheral and portal blood endothelin level was decreased; 4.ETA mRNA expression was increased in liver, expression located mainly in portal venule and hepatic arteriole around the portal area and that was dramatically increased in the venular wall.Conclusion:(1) Endothelin level of portal and peripheral blood was decreased gradually with the formation of liver cirrhosis and portal hypertension in r ats; (2)ETA m RNA e xpression w as i ncreased i n 1 iver m icrocirculation and up-regulated with the descending of endothelin level; (3) Special changes occurred in location of expression with the advance of liver cirrhosis.Postgraduate:Tang Tianping (General Surgery) Directed byProf. Zhou Yanbing...