Efflux of Drugs and Solutes from Brain: The Interactive Roles of Diffusional Transcapillary Transport, Bulk Flow and Capillary Transporters

We examined the roles of diffusion, convection and capillary transporters in solute removal from extracellular space (ECS) of the brain. Radiolabeled solutes (eight with passive distribution and four with capillary or cell transporters) were injected into the brains of rats ( n = 497) and multiple-time point experiments measured the amount remaining in brain as a function of time. For passively distributed compounds, there was a relationship...