Effect Of Chloroquine On The Induction Of Rat Uterine Peroxidase By An Oral Contraceptive

ABSTRACT Uterine peroxidase has been induced in immature female rate with estradiol and anovlar 21. Anovlar 21 is a steroid contraceptive containing 4 mg. norethisterone acetate (a progestin)t and 0.05 mg. ethinyl estradiol (an estrogen) per tablet. Maximum enzyme activity was found to occur 24 hours after oral administration of the contraceptive. The increased peroxidase activity accused by the eonbined steroids was inhibited by the administration of aycloheximide and puromycin (inhibitors of protein biospthe^isi. Peroxidase is thus synthesised da novo on the influence of the steroids. Chloroquine diphosphate has also been found to increase -the activity of peroxidase, with the maximum activity occurring 18 hours after ike drug has been ingected intramuscularly. Cycloheximide has been found to prevent this stimulatory effect of chloroquine. Chloroqidne was effective in increasing peroxidase activity in vivo: over a dose range of 0-20 mg/kg. body weight. It however* did not effect peroxidase activity in^ vitro. Chloroquine potentiated uterine peroxidase induction by anovlar 21, Chloroquine and/or anovlar 21 prevented "the production of litter by adult female rats.