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ﾊ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