Comparison of perfusates in the study of choline uptake by isolated rat livers

In a previous study it was shown that hepatic choline uptake is primarily a function of oxygen dependent choline oxidase activity. Studies measuring choline uptake demonstrated that the isolated perfused liver maintained with erythrocyte containing perfusates offered the most efficient conditions for this measurement. It was shown in guinea pig livers, essentially lacking in choline oxidase, that the oxygen carrying capacity of the medium is not critical to choline uptake. These studies suggest that when oxygen requiring systems are studied using the isolated perfused liver technique, ideally the perfusate should contain red blood cells.