title: Changes during development in transport processes of the blood-brain barrier.
abstract: The permeability of the blood-brain barrier to several classes of compounds was studied in rats between the ages of 15 days and 9 weeks. 14C-labelled test substances were injected simultaneously with two reference isotopes, 3H2O and 113mIn-labelled EDTA, into the common carotid artery followed by decapitation 10 s later. There was evidence that a monocarboxylic acid transport system in 15 to 23 day-old rats had a capacity at least six times greater than that present in adult animals. L-Lactate and acetate showed the highest permeability. At all ages there was a constant ratio between L-lactate and (-)D-3-hyroxybutyrate values. D-Glucose permeability increased with age, while that of several amino acids tested was the same in young and adult rats.
mesh_terms: D000375:Aging; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D001667:Binding, Competitive; D001693:Biological Transport, Active; D001812:Blood-Brain Barrier; D001921:Brain / Q000254:growth & development / Q000378:metabolism; D004492:Edetic Acid / Q000378:metabolism; D005947:Glucose / Q000378:metabolism*; D006885:Hydroxybutyrates / Q000378:metabolism*; D007773:Lactates / Q000378:metabolism*; D051381:Rats; D013217:Starvation; D014867:Water / Q000378:metabolism
chemical_list: D000596:Amino Acids; D006885:Hydroxybutyrates; D007773:Lactates; D014867:Water; D004492:Edetic Acid; D005947:Glucose