Water, Nitrogen, and Electrolyte Concentration in Brain

Chemical and functional changes in the organs of the body usually are attributed to the tissue components. If this is a correct conception, not only the composition and functional capacities of all of the tissue phases should be known but also the quantitative measurements of the relative amounts of these phases. Stimulated by these possibilities, numerous workers in the past few years have intensively studied the partition of electrolytes in mammalian tissue. Results of research on muscle, liver, kidney, and skin of the dog having already been presented, the defining of values for the distribution of water, nitrogen, and electrolytes in brain was the aim of this project. Utilization of these data for a comparison of the right and left cerebral hemispheres and of the hemisphere and the cerebellum also was planned. These findings would provide normal mean values for further investigative study of brain. There have been few histochemical studies on brain tissues. Tupikova and Gerard (1) published an abstract in 1937 on the salt content of neural structures; Yannet and Darrow in 1938 (2) contrasted the composition of skeletal muscle, liver, and brain in two groups of cats, a young group and an older group. Stewart-Wallace (3) in 1939 presented water and electrolyte data on human brain tissue obtained at autopsy. Manery and Hastings (4) in 1939 published data on brain from rats and rabbits. The present study includes analytical data on brains from twenty-two normal dogs apportioned as follows: five normal animals in each of which the right and left cerebral hemispheres were analyzed separately; five normal animals from which portions of fresh brain and ether-extracted portions from the same brain were analyzed; and twelve normal dogs from which serum, hemispheres, and cerebellums were analyzed.