Age and sex dependent alterations in PGF2α catabolism in the rat in vivo

Abstract 3 H-PGF 2α infused I.V. into male adult rats is transformed via 4 major enzymatic steps prior to being excreted in the urine. These steps include (1) 15-hydroxydehydrogenation (2) ‡13 reduction (3) β-oxidation and (4) a series of ω-oxidations, resulting in excretion of urinary products containing 14 and 16 carbon atoms. The first three steps occur at all ages; the fourth is essentially absent in rats younger than 24 days of age. Thus, urine from rats at 24 days of age contains one principal PGF 2α catabolite which was identified by GC-MS as 15-keto-13,14-dihydro-tetranor-PGF 2α (VII). That this product was an intermediate in the adult series of enzymatic reactions was shown by its re-infusion into adult rats which resulted in the appearance of radioactive adult-like products through additional ω-hydroxylation (II), ω-oxidation (V) and β-oxidation at the ω-end (III). Significant differences in the urinary profile of the male and female rats were observed at 72 days (adult) but not at 24 days.