The metabolism of [3H] pteroylglutamic acid in rat liver during regeneration after partial hepatectomy.

The rate of [3H] PteGlu uptake and of its incorporation into pteroylpolyglutamate derivatives at different times after label administration, was studied in the regenerating liver of rats 36 hr after partial hepatectomy. While 1 hr after administration of labelled PteGlu the radioactivity levels in regenerating livers are quite similar to controls, they are markedly higher 6, 12, 24 hr after label injection, which is mostly due to the high polyglutamate content. If the regenerating process, on the one hand does not modify the folate uptake rate, it does, on the other, increase the capacity for retaining folates, thanks to a more powerful ability to convert them into pteroylpolyglutamates.