The relationship between plasma biotin concentration and circulating leucocyte beta-methylcrotonyl-CoA carboxylase and propionyl-CoA carboxylase.

1. A newly developed biotin assay was used to monitor plasma and urinary biotin concentration after the oral administration of biotin. 2. In two normal subjects, leucocyte propionyl-CoA carboxylase and beta-methylcrotonyl-CoA carboxylase were markedly stimulated after the administration of biotin.