[Luteolysis in the pseudopregnant rabbit and endogenous prostaglandin (PG) F2 alpha (author's transl)].

The luteolytic properties of prostaglandin (PG)F2 alpha have been well established in several species. To ensure that endogenous PGF2 alpha is involved in luteolysis, two PGF2 alpha metabolites, 13,14-dihydroxy-15-keto PGF2 alpha (dhkPGF2 alpha) in blood and 5 alpha, 7 alpha-dihydroxy-11-ketotetranorprosta 1,16-dioic acid (PGF2 alpha UM) in urine, were measured in the pseudopregnant rabbit by radioimmunoassay. During pseudopregnancy marked increase in the two PGF2 alpha metabolites were demonstrated at about the time of luteal regression. Hysterectomy and intrauterine administration of indomethacin prolonged the life-span of corpora lutea in the pseudopregnant rabbit by 8 and 5 days, respectively, with no elevation of PGF2 alpha UM excretion. The results indicate that PGF2 alpha is a uterine luteolysin in the pseudopregnant rabbit as in other animal species.