Efficacy, acceptability, and clinical effects of a low-dose injectable contraceptive combination of dihydroxyprogesterone acetophenide and estradiol enanthate.

A total of 1,904 women, aged 15-38, used an injectable contraceptive combination of 90 mg dihydroxyprogesterone acetophenide with 6 mg estradiol enanthate, given once during each menstrual cycle between the 7th and 10th day, and preferably on the 8th day of the cycle, for a total of 17,576 cycles. Of these 1,904 women, 1,197 completed 12 cycles of use of the injectable combination. One subject became pregnant during the trial, resulting in a cumulative pregnancy rate of 0.07%. Principal reasons for discontinuation were personal, non-medical reasons, such as lost to follow-up, no longer wished to continue, protocol violation, desire to change to another contraceptive method, moved away, or other personal reasons. Mean weight of 1,901 subjects at admission to the trial was 53.5 +/- 0.2 kg and this increased to 54.3 +/- 0.3 kg after 12 cycles of use. Approximately 50% of subjects experienced menstrual bleeding similar to normal throughout the study period. The most frequent menstrual abnormality was irregular bleeding, experienced by approximately one-third of subjects.

Multicenter, double-blind, comparative clinical study on the efficacy and acceptability of a monthly injectable contraceptive combination of 150 mg dihydroxyprogesterone acetophenide and 10 mg estradiol enanthate compared to a monthly injectable contraceptive combination of 90 mg dihydroxyprogesterone acetophenide and 6 mg estradiol enanthate.

Healthy, regularly menstruating women, aged 14-38 years, were enrolled in a comparative, double-blind, phase III, clinical trial to evaluate the contraceptive efficacy and acceptability of a combination of 90 mg dihydroxyprogesterone acetophenide with 6 mg estradiol enanthate compared to the commercially available contraceptive combination of 150 mg dihydroxyprogesterone acetophenide with 10 mg estradiol enanthate. Subjects received the contraceptive combination intramuscularly, between the 7th and 10th day of each menstrual cycle, during 12 consecutive menstrual cycles. Approximately 60% of the subjects in both groups completed the study. Principal reasons for discontinuation were personal, nonmedical reasons. Principal medical reasons for discontinuation were menstrual-related, irregular bleeding being the most frequent. Differences in menstrual patterns between the two groups did not lead to differences in discontinuation rates. Three contraceptive failures occurred during the trial, one in Group A (90/6 mg) and two in Group B (150/10 mg), indicating that the lower dose formulation is at least as efficient as the higher dose.

A potential role for catecholamines in the development and progression of carcinogen-induced mammary tumors: hormonal control of beta-adrenergic receptors and correlation with tumor growth.

In order to gain further knowledge on the beta-adrenergic receptor system in DMBA-induced rat mammary tumors, we have studied the correlation between changes in tumoral beta-adrenergic receptor concentration and distribution, progesterone receptor status and tumor growth after ovariectomy and treatment with various ovarian and adrenal steroids, or induction of hyperprolactinemia. Autoradiographic localization of beta-adrenergic receptors in ovariectomized (OVX) animals shows very weak labeling with [125I]cyanopindolol. In these tumors, the connective tissue is predominant, while the epithelial cell content is very low. Similarly, when direct measurements of [125I]cyanopindolol are performed with membrane preparations, beta-adrenergic receptor concentration is sharply reduced 2-3 weeks following ovariectomy or treatment with LHRH against [D-Trp6, des-Gly-NH2(10)]LHRH ethylamide. This effect on the beta-adrenergic receptor population in the tumor is accompanied by the well known effect of castration on tumor growth and progesterone receptor levels, namely a marked regression of tumor growth and a significant decrease in progesterone receptor concentration. Treatment of OVX rats with 17 beta-estradiol (E2) alone or in combination with progesterone (P) caused a highly significant increase in beta-adrenergic and progesterone receptor levels, as well as tumor growth. A similar sharp increase in the value of the three parameters studied was observed following daily treatment of OVX rats with dehydroepiandrosterone (DHEA) or androst-5-ene-3 beta,17 beta-diol (5-ene-diol). The autoradiographic localization of beta-adrenergic receptors in OVX rats treated with 5-ene-diol showed that the epithelial cells were numerous with a high degree of labeling. On the other hand, treatment of OVX animals with the androgen dihydrotestosterone (DHT) did not produce significant changes in beta-adrenergic receptor levels or tumor growth. Finally, endogenously-induced hyperprolactinemia by implanting three anterior pituitary glands under the kidney capsule of OVX animals resulted in a significant increase in beta-adrenergic and progesterone receptor levels as well as tumor growth. The positive correlation observed between changes in beta-adrenergic receptor concentration, progesterone receptor levels and tumor growth indicates a high sensitivity of the beta-adrenergic receptor population of DMBA-induced rat mammary tumors to the hormonal milieu, and suggests that the beta-adrenergic receptor system may represent a valuable parameter of hormone responsiveness.

Beta-adrenergic receptors in DMBA-induced rat mammary tumors: correlation with progesterone receptor and tumor growth.

In order to gain further knowledge about the potential role of catecholamines in mammary carcinoma, we have used the potent beta-adrenergic antagonist cyanopindolol (CYP) as iodinated ligand to characterize beta-adrenergic receptors in membranes prepared from mammary tumors induced by dimethylbenz(a)anthracene (DMBA) administration in the rat. The binding of [125I]CYP to membrane preparations of DMBA-induced rat mammary tumors is rapid at room temperature, reaching half maximal specific binding at 30 min of incubation. Scatchard analysis of the data indicates that [125I]CYP binds to a single class of high affinity sites (114 +/- 2.1 fmoles/mg protein) at an apparent KD value of 38.0 +/- 0.3 pM. The order of potency of a series of agonists to compete for [125I]CYP binding is consistent with interaction with a beta 2-subtype receptor: zinterol greater than (-)isoproterenol greater than (-)epinephrine much greater than (-)norepinephrine. In addition, the potency of a series of specific beta 1 and beta 2 synthetic compounds to displace [125I]CYP in mammary tumors is similar to their potency in typical beta 2-adrenergic tissues. The binding of [125I]CYP to DMBA-induced rat mammary tumors shows a marked stereoselectivity, the (-)isomers of isoproterenol and propranolol being 150 and 80 times more potent, respectively, than their respective enantiomers. The autoradiographic localization of [125I]CYP performed on frozen sections revealed the presence of specific beta-adrenergic receptors in all the malignant cells. Spontaneous mammary tumors of aging (18-22 months) female rats have high levels of beta-adrenergic receptors. Castration decreased the concentration of [125I]CYP binding sites in DMBA-induced mammary tumors. A close correlation was observed between progressing, static, and regressing tumors after ovariectomy and beta-adrenergic receptor concentration. The presence of beta-adrenergic receptors in mammary tumors as well as the modulation of their level by ovarian hormones provides a mechanism for catecholaminergic influence in mammary cancer tissue.

Additive inhibitory effects of bromocryptine (CB-154) and medroxyprogesterone acetate (MPA) on dimethylbenz[a]anthracene (DMBA)-induced mammary tumors in the rat.

Treatment for 18 days of rats bearing dimethylbenz[a]anthracene-induced mammary tumors with the synthetic medroxyprogesterone acetate (MPA) or the inhibitor of prolactin secretion 2 alpha-bromocryptine (CB-154) inhibited total tumor area to 30 +/- 7% of the original volume. Combination of the two drugs, on the other hand, caused further inhibition to 10 +/- 5% of the pretreatment tumor area. The most striking effect of combination of the two drugs is a doubling of complete responses (no detectable tumor) from 30% when either drug was used alone to 60% in animals treated with the combination therapy. Both estradiol and progesterone receptors were further decreased when MPA was added to CB-154. The present data demonstrate that combination of the synthetic progestin MPA and the inhibitor of prolactin secrection CB-154 exerts maximal inhibitory effects on the growth of the DMBA-induced mammary tumor, the most widely used in vivo model of human breast cancer.

Effects of the aromatase inhibitor 4-hydroxyandrostenedione and the antiandrogen flutamide on growth and steroid levels in DMBA-induced rat mammary tumors.

Using dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in the rat as model, comparison was made of the effect of treatment for 20 days with the aromatase inhibitor 4-hydroxyandrostenedione (4-OH-A) (7.5 mg, twice daily) or the antiandrogen flutamide (5 mg, twice daily) on tumor growth as well as on plasma and tumor content of estrogens, androgens, and their precursors and metabolites. Tumor number and size were markedly decreased following treatment with either drug, the effect of treatment being more important on size than number, and on new tumors which developed during treatment than on tumors already present at start of treatment. Treatment with the aromatase inhibitor 4-OH-A caused a parallel decrease in plasma and tumor levels of pregnenolone (Preg), progesterone (P), and 17-OH P, while there was a marked increase in dehydroepiandrosterone (DHEA), androst-5-ene-3 beta,17 beta-diol (delta 5-diol), androstenedione (delta 4-dione), testosterone (T), androstane-3 alpha, 17 beta-diol (3 alpha-diol), and androstane-3 beta,17 beta-diol (3 beta-diol), with no significant change in dihydrotestosterone (DHT) and 17 beta-estradiol levels. The marked increase in tissue T content coupled to a decrease in P levels could well contribute to the inhibition of tumor growth induced by 4-OH-A. Flutamide, on the other hand, caused a marked fall in plasma and tissue levels of Preg, 17-OH Preg, P, and 17-OH P, with no significant change in the concentration of the other steroids, thus suggesting a possible role of the fall in tissue P levels in the inhibition of tumor growth. Since both drugs are potent inhibitors of DMBA-induced tumor growth in intact animals, better knowledge of their mechanism of action should add to our understanding of the multiple endocrine factors controlling the growth of these tumors.

Adrenal steroids stimulate growth and progesterone receptor levels in rat uterus and DMBA-induced mammary tumors.

We have studied the effect of treatment with the adrenal steroids androst-5-ene-3 beta,17 beta-diol (delta 5-diol) and dehydroepiandrosterone (DHEA) on the growth and progesterone receptor levels of dimethylbenz(a)anthracene (DMBA)-induced mammary tumors in the rat. While the total number of tumors in ovariectomized animals was 0.60 +/- 0.19 tumor per rat after 24 days, it increased to 2.54 +/- 0.50 (p less than 0.01) and 1.42 +/- 0.26 (p less than 0.01) in the delta 5-diol and DHEA (2 mg, twice daily) treated animals, respectively. While very few new tumors developed during a 24-day period in ovariectomized animals (0.07 +/- 0.07/rat), an average of 0.47 +/- 0.19 (p less than 0.05) new tumor per animal appeared in intact rats. In ovariectomized animals treated with delta 5-diol or DHEA, the numbers of new tumors were 0.77 +/- 0.26 (p less than 0.05) and 0.42 +/- 0.15 (p less than 0.05), respectively. An even more striking effect was observed on average total tumor area, which decreased from 4.70 +/- 0.95 cm2 in intact animals to 0.75 +/- 0.27 cm2 (p less than 0.01) following ovariectomy. Values of 9.79 +/- 2.25 (p less than 0.01) and 3.93 +/- 0.86 cm2 (p less than 0.01) were found in the delta 5-diol- and DHEA-treated ovariectomized animals, respectively. Treatment of ovariectomized animals with delta 5-diol and DHEA caused a marked increase (p less than 0.01) in progesterone receptor levels in both the uteri and DMBA-induced mammary tumors. Uterine weight was also stimulated (p less than 0.01) by treatment with the two adrenal steroids.(ABSTRACT TRUNCATED AT 250 WORDS)

Impaired steroidogenesis in the luteal phase of the reproductive cycle and during pregnancy in rhesus monkeys immunized with the beta-subunit of ovine luteinizing hormone.

Monkeys immunized with the beta-subunit of ovine luteinizing hormone (oLH beta) develop antibodies which cross react with rhesus chorionic gonadotropin (rhCG) and luteinizing hormone (rhLH). Immunization causes shortened menstrual cycles and reduced fertility. Fertility can be restored by administration of medroxyprogesterone acetate (MPA) during the first 5 weeks of pregnancy. In the present study, we have measured the effects of circulating oLH beta-antibodies on peripheral estradiol, progesterone and 17 alpha OH-progesterone (17OH-P) concentrations throughout the menstrual cycle and during gestation in monkeys which became pregnant following MPA-treatment. Progesterone concentrations were markedly reduced during the luteal phase in cycling animals and the luteal phase of the cycle was significantly shorter as compared to non-immunized controls. Concentrations of estradiol and 17OH-P in the peripheral circulation were not affected by the oLH beta-antibodies. In immunized monkeys which became pregnant following MPA-treatment, progesterone and 17OH-P levels were consistently lower and estradiol concentrations were increased during the second and third trimesters. Our results show that circulating antibodies to oLH beta have multiple endocrinological effects. Corpus luteum function is impaired in cycling monkeys and during the early part of pregnancy. In addition, the pattern of steroid secretion remains abnormal in pregnant monkeys even after the luteal-placental shift.