[Effects of propionic acid metabolic precursors in biotin-deprived rats]

Biotin deficiency induced in the rat, with a biotin-deficient diet but with added avidin involves clinical symptoms of deficiency as well as an important drop (80%) in propionyl-CoA carboxylase activity in the liver, heart and kidneys. But major biochemical anomalies (ketoacidosis and increased urinary elimination of propionic acid), characteristic of propionic acidaemia due to propionyl-CoA carboxylase deficiency in man, are not observed in the rat. Nevertheless, abnormal urinary elimination of methylcitrate and tiglylglycine reflects an appreciable decrease in the metabolism of propionyl-CoA in these animals. The propionyl-CoA load caused by the administration of metabolic precursors of this substance, mainly L-isoleucine, does not induce important biochemical variations except for excretion of propionylglycine.