An indicator-dilution technique for study of blood-to-brain solute passage in the rat.

MURRAY, JOEL ELISABETH, AND AUDRIUS PLIOPLYS. A n indicatordilution technique for study of blood-to-brain solute passage in the rat. J . Appl. Physiol. 33(5): 681-683. 1972.-Details arc given of a method adapting single-injection indicator-dilution techniques for use in the study of blood-to-brain solute transport in vivo in the rat. Glucose extraction by brain is shown to be saturable under conditions of high circulation plasma glucose concentrations. Investigation of functional vascular anatomical relationships was made with a view toward how effectively the brain of the rat may be isolated as an "organ" for indicator-dilution studies. Indicatordilution curves obtained during simultaneous collection of venous efluent from the confluens of sinuses and the external jugular vein suggest that blood from the sinus does not contain significant admixture of extracerebral venous return and may therefore be relied on to provide information about solute extraction by brain in the rat. economy in costs for animals and supplies over studies using large mammals.