RESUMEN
Spectrophotometric assays have been used to determine FA concentration in tissue homogenates from various organs (liver, kidneys, brain, spleen) in white rats; these studies were undertaken to test the age--and organ--dependent variations of FA concentrations in tissue homogenates. The results showed a marked decrease of FA concentration in the adult group of rats when related to the young group, and in the aged group when compared to the adults respectively. Analysing the determined values of folates in tissue homogenates of various organs (in rats belonging to the same group of age), the highest concentration has been found in the liver homogenate, followed in decreasing order by kidneys and to a much greater distance, by the brain and spleen.