Thiamine mono- and diphosphate splitting enzymes in the pre- and postmetamorphic Pelobates syriacus

Abstract

1. 1. The ontogenic development of enzymes participating in the dephosphorylation of thiamine mono- and diphosphates was investigated in Pelobates syriacus. The developmental stages examined were between tadpoles possessing hind limbs and animals of about 20 days after the end of metamorphosis. 2. 2. The enzymatic activity was determined by incubating thiamine monophosphate and thiamine diphosphate with liver tissue, under standard conditions and by identifying the products by paper chromatography. 3. 3. Both thiamine mono- and diphosphate splitting enzymes were present in all the pre- and postmetamorphic stages. 4. 4. The results obtained seem to indicate that the activity of the investigated enzymes at pH 9 is higher after the completion of metamorphosis than before and continues to rise during early postmetamorphic life. 5. 5. A general developing line of the activity of different phosphatases according to the metamorphic stage of the tadpoles has been suggested.