New method for measurement of hepatic blood flow in the rat using thermodilution method

A new method for measurement of hepatic blood flow in the rat is described. The method involved the use of a thermodilution technique. A thermistor probe was placed in a right hepatic vein of the median lobe of the liver, and a thermal indicator was injected into the portal vein via a catheter. The hepatic blood flow was then estimated from changes in the blood temperature. Measured hepatic blood flow was 25.6 +/- 2.3 ml/min (mean +/- SD, n = 17) or 2.80 +/- 0.45 ml/min/g liver. These results are in a good agreement with other studies that used different techniques to estimate total hepatic blood flow in the rat. To verify this method, an in vitro isolated liver perfusion model was used. The actual flow rates determined by time collection of outflow and the measured flow rates estimated by the thermodilution technique were well correlated (r = 0.968, less than P .001). This new technique is simple and accurate and can be used for repeated serial measurements of hepatic blood flow in the same animal.