Effect of Triethyl Tin on Brain and Skeletal Muscle

During the course of a number of studies of the blood-brain barrier, the urgent need for good physiological measurements of the size of the functional compartments (extracellular space, glial space, neuronal space, etc) of the central nervous system became apparent. In one of these studies the volume of distribution of sucrose in the CNS was investigated. It was observed that sucrose distributed in two compartments of the brain at markedly different rates. On this basis it was suggested that the compartment with the shortest half-time for sucrose entry was the extracellular space and that the other compartment was the intracellular, composed of one or more cell types, possibly glial cells.14 Triethyl tin (TET) in very small quantities causes cerebral edema, shown by Torack et al19 to be confined to the glial cells although other workers have suggested that TET edema is extracellular.11 Luse and Harris10 have shown that the cerebral edema produced in rabbits by craniotomy or intravenous distilled water is located in glial processes. Aleu et al2 concluded that the edema produced by is confined primarily to the white matter and consists of "intramyelinic vacuoles" of fluid similar in composition to extracellular fluid. If the slow component of the uptake of sucrose by the brain is due to sucrose entry into glial cells and if glial cells are the primary sites of fluid accumulation in TET edema, the volume of distribution and possibly the rate of uptake of sucrose into the brain of TET-treated animals should be altered. Such alterations might indicate whether sucrose could be used to measure the com¬ bined volume of the extracellular space and the glial compartment. Therefore, a com¬ parison was made of the rate of uptake and volume of distribution of sucrose in brain and muscle of control and TET-treated animals. Changes in brain electrolytes have been shown to accompany the cerebral edema produced by TET. In 1957, Magee et al u reported that brain Na content of rats was markedly increased by TET while con¬ tent was decreased slightly or not changed when calculated on a dry weight basis. Re¬ cently Aleu et al2 reported the effect of