Methodological aspects of glucose monitoring with a slow continuous subcutaneous and intravenous ultrafiltration system in rats

A method for the continuous ultrafiltration of venous blood or subcutaneous fluid is demonstrated with glucose monitoring in the living rat. Ultrafiltrate was withdrawn at a constant flow rate of approximately 100 nl/min. Glucose content of the ultrafiltrates was electrochemically determined with a flow injection analysis method and a bi-enzyme reactor. After glucose loading, the time course of glucose in the ultrafiltrate from the jugular vein was virtually identical, whereas that from the subcutaneous compartment was attenuated and the peaks blunted as compared to glucose levels in concomitantly assayed arterial blood. Our study demonstrates the potential of low rate ultrafiltration for monitoring metabolism with biosensor technology in vivo. (C) 1997 Elsevier Science Limited.