Lower limits of cerebrovascular permeability to nonelectrolytes in the conscious rat

摘要: Am. L Physinl.: 2kart I&c*. 2hyCL $3): H299-~3~1j 1978. - Vascular permeability P in different cerebral regions of the conscious rat was determined, independently blood flow, for “C tracers glycerol, mannitol, sucrose, and inulin. A tracer injected intravenously, arterial plasma concentrations were monitored, regional brain measured at specific times thereafter. plasma-brain two-compartment model used to calculate mean values P, letting capillary area equal 240 cm”*g? Z4 X 10+ cm * s-* 0.95-1.4 lop7 2.53,O x 10mH 1.0-1.4 IO-!) Cerebrovascular coefficients correspond single cell membranes lipid bilayers, but are 1,000 less than muscle capillaries, The relation between cerebrovascular prmeability octanol/water partition suggests that saccharides diffuse into through homogeneous endothelial not pores or by means vesicles. Estimated distribution volumes indicate glycerol distributes rapidly within extracellular intracellular compartments may be incorporated metabolic pool, mannitol extracellularly partially intracellularly, sucrose remains space.