INHIBITION BY ESTROGEN ADMINISTRATION OF ADRENAL-PITUITARY RESPONSE TO METHOPYRAPONE

Increased adrenocortical responsiveness to exogenous ACTH in oral contraceptive users

To evaluate the effects of changing steroid milieu on adrenocortical function, basal levels and responses of cortisol, 17-hydroxyprogesterone (17PO), androstenedione (A), dehydroepiandrosterone (DHEA), and testosterone to exogenous synthetic ACTH were investigated in six normal women during the early follicular (EF) and midluteal (ML) phases of the menstrual cycle and in five women on an oral contraceptive (OC) agent (35 micrograms ethinyl estradiol and 1 mg ethynodiol diacetate, Demulen). Baseline serum steroid and cortisol binding globulin (CBG) levels were measured on days 3-7 and 21-23 of the menstrual cycle in the normal subjects and on days 3-7 of OC treatment cycles. ACTH stimulation (10 micrograms m-2 i.v. bolus) was performed following dexamethasone suppression (0.5 mg p.o. q 6 h X 4). Basal levels of cortisol and CBG as well as cortisol responses to ACTH were increased in OC users relative to normal women tested during both the EF and ML phases of the cycle. In addition, 17PO levels were increased during the ML phase both before and following dexamethasone suppression compared to levels present in the EF phase and in OC users, no doubt because of increased ovarian steroidogenesis.

Effect of some contraceptive steroids on growth and development of salivary glands and incidence of dental caries in female rats

Synthetic contraceptive steroids, ethynylestradiol and medroxyprogesterone acetate, were given individually in different doses to weanling female rats for eight weeks. In proportion to the doses administered, ethynylestradiol inhibited and medroxyprogesterone acetate stimulated the growth and development of the salivary glands. The steroid-treated rats exhibited an increase in dental caries incidence as compared to controls.