Alterations to hepatic microcirculation in thioacetamide-induced cirrhotic livers of rats

In liver cirrhosis, increased resistance of intrahepatic microvasculature contribute to the development of portal hypertension. This study aimed to reveal the alterations to hemodynamics in microvasculature of thioacetamide-induced fibrotic and cirrhotic rat livers, using in vivo microscopy. In fibrotic livers, although intrahepatic blood flow remained unaltered, area percentage of sinusoids was significantly decreased. In cirrhotic livers, intrahepatic blood flow was significantly increased concurrently with decrease in area percentage of sinusoids. The flow velocity and volume flow were significantly increased in terminal portal venules (TPVs) without changes in vascular diameters, whereas all these parameters were not altered in terminal hepatic venules (THVs). Intrahepatic shunts which emerged from TPVs and ran toward THVs, and anastomoses between neighboring THVs were formed in cirrhotic livers. These data indicate that the first occurring alteration of microcirculation in liver cirrhosis is decrease in sinusoidal beds.