Assessment of Kupffer cell function in rats with chronic liver injury caused by CCl4

Kupffer cell function was assessed by using scintigraphy to evaluate the turnover of a metabolizable tracer (99mTc-millimicrosphered albumin). The organ uptake rate of the tracer, and new parameters concerned with the degradative functions of Kupffer cells obtained from analysis of the excretion phase of the hepatic time-uptake rate curve, were measured in rats with two different types of chronic liver damage induced by carbon tetrachloride (fatty liver group and liver cirrhosis group). The hepatic uptake rate in chronic liver injury decreased, while in contrast the splenic and pulmonary uptake rates increased. A particularly high uptake by the lungs was observed. The data demonstrated a reduced phagocytic activity of the Kupffer cells in rats with chronic liver injury. The new parameters concerned with Kupffer cell degradative function; i.e. the excretion rate (K) and the degradation rate in the first 60-min (D60), were markedly decreased even in the early stage of chronic liver injury. The data showed that the impairment of Kupffer cell degradative function occurred even earlier in liver damage than impairment of the phagocytic activity, so that the K value and the D60 value were the more sensitive indicators of Kupffer cell function.