STUDIES ON HOMOPANTOTHENIC ACID : (IV) UPTAKE OF HOMOPANTOTHENIC ACID BY RAT BRAIN

Abstract

On comparing the uptake of homopantothenic acid (HOPA) and pantothenic acid (PaA) into brain of rat after intraperitoneal injection, it was shown that HOPA penetrated into the central nervous system as readily as PaA did. The penetration of HOPA into eight regions of rat brain has been measured. The marked regional differences were not observed and pre-treatment with hydroxymethylpyrimidine produced little change in the concentration of HOPA in brain regions. The experimental data of the accumulation of HOPA and γ-aminobutyric acid (GABA) by brain slices suggest that HOPA is passively transported by brain in vitro while GABA is actively transported. Almost all of HOPA orally administered was excreted in urine by mice in 24 hours. More than 95 percent of urinary metabolites was HOPA and less than 5 percent was an unknown metabolite.