Kinetics of protein binding determine rates of uptake of drugs by brain

P. J. Robinson and S. I. Rapoport

$capillaries; transit time; extraction; restrictive elimination; concentration barrier; permeability mathematical modeling; profile; bilirubin; blood- MANY DRUGS OTHER BIOLOGICALLY active compounds (henceforth simply referred to as drugs) are known to bind to plasma s, especially albumin. In cerebral similar capillaries (e.g., in nerve, inner ear, retina), which are essentially impermeant to large molecules, only the free fraction of the drug in plasma is considered available for diffusion or transport across the capillary walls (see, for example, Ref. 20). The degree of of a substance is thus important in determining its by an organ. Consequently, differences in due to genetic, environmental, or pathological factors, as well as to aging, may markedly affect the of such substances. can prolong the therapeutic effectiveness of a drug by reducing its rate of excretion providing a source for its long-term action. Very tight , however, reduces the concentration of free drug available for diffusion into the (20). Drug by albumin depends on interaction between the lipoid regions of drug , just as membrane permeability depends on interactions between lipoid regions of drug membrane. Both effects are proportional to lipid solubility (20). R1212 Two independent characteristics of need to be taken into account in determining$

Kinetics of protein binding determine rates of uptake of drugs by brain

P. J. Robinson and S. I. Rapoport

Follow AJP - Regulatory, Integrative and Comparative Physiology , Volume 251: R1212 The American Physiological Society – Dec 1, 1986