Assessment and histological analysis of the IPRL technique for sequential in situ liver biopsy

This paper describes a technique for obtaining two full and one partial lobe biopsies from the liver in situ during an IPRL experiment. Our approach of retaining the liver in situ assists in minimising liver capsule damage, and consequent leakage of perfusate, maintains the normal anatomical position of the liver during perfusion and helps to keep the liver warm and moist. Histological results from sequential lobe biopsies in control perfusions show that cytoplasmic vacuolation of hepatocytes is a sign of liver deterioration, and when it occurs it commences as a diffuse pattern which tends to develop a circumscribed, centrilobular pattern as perfusion progresses.Liver lobe biopsies obtained using this method can be used to study temporal effects of drug treatments and are suitable for light and electron microscopy, and biochemical analyses.The isolated perfused rat liver (IPRL) is a well characterised model which is commonly used to study the biology and pathobiology of the liver in various experimental settings [1-3]. IPRL has a wide range of applications, including ischemia-reperfusion [4], biochemistry [5], pharmacology [6] and immunology [7]. Previous and ongoing studies in our laboratory have used this model to examine the hepatotoxicity of kava [8].Liver lobe biopsies during IPRL enable temporal profiles of treatments to be observed in each liver. Lobe biopsy techniques have been described using microsurgical techniques in live rats [9,10], and in perfused rat livers post hepatectomy [11]. However, detailed written and pictorial instructions for taking in situ, post mortem lobe biopsies are lacking. Here we describe an uncomplicated technique for obtaining two full and one partial liver lobe biopsy from liver in situ during an IPRL experiment, and corresponding control histological results. The histological architecture of the rat liver under these conditions is also discussed.The liver of the anaesthetised rat is isolated and perfused as described in methods