Yasusuke Masuda and Tamami Oguma
Division of Toxicology, Niigata College of Pharmacy, 5-13-2, Kamishin'ei-cho, Niigata 950-2081, Japan
Abstract: We previously reported that intrahepatic flow disturbance can be detected by vital staining of the liver with a fluorescent dye (Masuda╩et al., Biochem Pharmacol, 53, 1779-1787 (1997)). To evaluate further use of this method, a detailed study was performed. The isolated perfused rat liver was vitally stained with rhodamine 6G (R-6G) and perfusion-fixed, and cross and horizontal sections were examined by fluorescence microscopy. In the control liver, R-6G staining was localized to periportal hepatocytes and was distributed evenly throughout the liver, indicating a homogeneous perfusion. Finer examination of the thick sections and reconstruction of a three-dimensional flow pattern revealed intricate vascular networks together with the sinusoids in different portions of the liver. In a flow-redistribution model, i.e., under hepatic nerve stimulation, the extensive flow redistribution to the deeper portion of the liver was found to occur via short branches sprouted from large portal veins, with minimal perfusion of the liver margin. Thus, visualization of hepatic microvasculature enables anatomical analysis of flow disturbance. The method is indirect but simple and may help detect intrahepatic flow disturbance that could be evoked by various factors.
Keywords: Intrahepatic flow disturbance, Hepatic vascular network, Rhodamine 6G,
Isolated perfused rat liver, Hepatic nerve stimulation