Hamamatsu H
Department of Internal Medicine, School of Medicine, Keio University, Tokyo, Japan.
Arukoru Kenkyuto Yakubutsu Ison. 1993 Dec;28(6):467-82.
Hepatic microcirculation is thought to be closely associated with the liver function. The present study was aimed to quantify changes in hepatic microcirculation after acute ethanol administration using a photometric device. Male Wistar rats were anesthetized with pentobarbital sodium (35 mg/kg) intraperitoneally. After laparotomy, a lobe of the liver was exposed and placed on the cover glass at the window of plastic stage, and observed using inverted intravital fluorescence microscopy assisted by a silicon intensified target camera. Erythrocytes were labeled with fluorescein isothiocyanate (FITC) according to the method of Zimmerhackl et al, and injected from the catheter placed at the aortic arch. FITC-labeled red blood cells (FITC-RBCs) recirculated continuously and resembled native cells in their flow properties. Ethanol (20%; 3 g/kg, 30%; 4.5 g/kg, 40%; 6 g/kg) was administered through the stomach tube. The microfluorograph of hepatic microcirculation was then recorded on a videotape. The velocity of FITC-RBCs in sinusoids was measured with a multipurpose computerized image analyzing system by replaying the video images. Portal pressure, mean arterial pressure, and central venous pressure were also monitored. The velocity of FITC-RBCs in the sinusoid increased by 54% at 10-20 min after 20% ethanol administration and remained at higher than the basal level throughout the period of the experiment. The velocity after 30% ethanol administration increased in some experiments and decreased in the others at the end of the experiment (60 min after acute ethanol administration). However, the velocity decreased by 26% at 60 min after 40% ethanol administration. Portal pressure increased by 16% at 45-60 min after 20% ethanol administration, and increased by 23% at 30 min after 40% ethanol administration, while mean arterial pressure and central venous pressure had no significant change. The method in this study is the first approach to visualize hepatic microcirculation by FITC-RBCs and measure erythrocyte velocity in the sinusoid using a multipurpose computerized image analysis system. The current results suggest that high concentration of ethanol may disturb hepatic microcirculation at the sinusoidal level.
