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At least 109 records · Page 6Linked to original sources
PubMed1983

Plasma lipid changes and medroxyprogesterone acetate.

Progestogens may have profound effects on lipid metabolism. Effects are generally dose-related and are more pronounced with 19-nor testosterone derivatives. Progestogens suppress circulating levels of high-density lipoprotein cholesterol (HDL-C) and increase circulating low-density lipoprotein cholesterol. Therefore, over a long period of time, the risk of atherosclerosis may increase. Although contraceptive use of depot medroxyprogesterone acetate (DMPA) reduced HDL-C levels by 15-20%, the levels generally remain within the normal range. Progestogens such as DMPA usually do not have any influence on fasting triglyceride levels. Some progestogens produce changes in the composition of phospholipids, but not DMPA. Progestogen effects on lipid metabolism are different from estrogen effects alone or estrogen-progestogen combinations. Increased risk of cardiovascular disease in longterm DMPA users is probably very small, but may become more significant when coupled with high risk factors. 10 years ago, most of the undesirable metabolic changes associated with the use of oral contraceptives were attributed to the estrogen component. 2 recent findings illustrate that certain progestogens can create metabolic havoc. 1) There is a strong association between depressed circulating levels of HDL-C and risk of serious cardiovascular disesase. 2) Certain progestogens are capable of substantially depressing the circulating levels of HDL-C, whereas estrogen actually elevates HDL-C. This does not prove that progestogens cause cardiovascular disease, but this possibility should be considered.

Biology↗
PubMed1983

Oral contraceptive steroids impair the elimination of theophylline.

The influence of OCS and sex differences on the disposition of theophylline has been studied in 12 healthy young men (29 +/- 4 years old), 13 healthy young women (29 +/- 12), and 10 healthy young women (24 +/- 3) receiving OCS for a period greater than 6 months. The elimination t1/2 was longer in women taking oral contraceptives (523 +/- 110 min) than in women not on oral contraceptives (386 +/- 157). Weight-normalized plasma clearance of theophylline was less in women taking oral contraceptive steroids (0.70 +/- 0.15 ml X min-1 X kg-1) than in women not on oral contraceptive steroids (0.98 +/- 0.32). Plasma binding and volume of distribution were not different between the two groups of women. Weight-normalized clearance, weight-normalized volume of distribution, plasma t1/2, and plasma binding were not different between men and women not taking OCS.

Adult↗
PubMed1980

[Amenorrhoea following oral contraception. Pathophysiological problems (author's transl)].

In women with previously normal menstrual cycles the hypothalamus-pituitary-ovarian function returns to normal within one month after anovulatory steroids are discontinued, and although the follicular phase is prolonged, the ovulation mechanisms are restored within 3 to 4 weeks. Oral contraception by itself does not produce amenorrhoea, but it may mask possible disorders in the gonadotropic axis. Thus, in many cases post-contraceptive amenorrhoea indicates previous dysfunction of the anterior pituitary, which appears to involve lack of oestradiol positive feed-back and, to a greater extent, excessive negative feed-back. Following oestradiol administration, gonadotropic inhibition is abnormally prolonged beyond the 15th day. Cyclic activity is usually restored by clomiphene citrate. Post-contraceptive amenorrhoea is sometimes accompanied by galactorrhoea. Oestrogens facilitate prolactin secretion by producing hypertrophy and hyperplasia of pituitary prolactin-producing cells, but progestogens probably have an inhibitory effect on these cells, so that prolactin plasma levels are normal or slightly raised during treatment with anovulatory steroids. A pituitary microadenoma should be suspected in the presence of high prolactin levels, and oestrogenic treatments should be stopped. In all cases of amenorrhoea, whether or not they occur after oral contraception, the same etiological investigations should be carried out.

Amenorrhea↗
PubMed1992

Combined effects of RU486 and tamoxifen on the growth and cell cycle phases of the MCF-7 cell line.

The antiproliferative effect of RU486 and its effect combined with tamoxifen on the growth and cell cycle kinetics parameters on the MCF-7 human carcinoma cells were investigated. When MCF-7 cells in the exponential growth phase were treated with RU486 (10(2) nmol/L), a time-dependent cell growth inhibition was observed which was significant 5 days after the beginning of treatment. This inhibition was accompanied by a time- and dose-dependent decrease in the percentage of S and G2-M phase cells and a concomitant increase in the percentage of cells in the G0/G1 phase of the cell cycle. With tamoxifen (10(5) pmol/L), growth inhibition was obtained after 4 days of treatment of cells, and the blockage of the cell cycle occurred in the G0/G1 phase. In the case of simultaneous treatment of MCF-7 cultures with RU486 (10(2) nmol/L) and tamoxifen (10(5) pmol/L), we observed a synergistic inhibitory effect on the proliferative rate for short treatment (less than or equal to 3 days), whereas RU486 or tamoxifen alone had no effect. For the intermediate treatment (4 days), the combined effect of RU486 and tamoxifen was not significant compared to the effect of tamoxifen alone. For the long treatment (greater than 4 days), there were no differences between the number of cells in the treated cultures under different experimental conditions, but all were inhibited compared to those in control cell cultures. This simultaneous treatment of cells does not induce any change in the distribution of cells in the different cell cycle phases compared to tamoxifen percentages. These results suggest that RU486 is a cell cycle phase-specific growth inhibitory agent, and a combination of antiestrogen/antiprogestin should be considered as a possible improvement in breast cancer endocrine therapy.

Breast Neoplasms↗
PubMed1984

Regulatory effect of contraceptive steroids on the release of tissue-type plasminogen activator in vitro.

The release of tissue-type plasminogen activator (t-PA) from incubated specimens of human veins was investigated by an immunoradiometric determination of the concentration of t-PA in the medium. The initial release of t-PA was strongly correlated to the weight of the incubated specimens. T-PA was not demonstrable after the third day of incubation. The addition of d-norgestrel (83.3 ng/ml) to the medium significantly stimulated the release of t-PA; whereas, ethinylestradiol (16.6 ng/ml) did not have an effect.

Adult↗
PubMed1999

A comparison of tamoxifen and misoprostol to misoprostol alone for early pregnancy termination.

A study was undertaken to determine whether the combination of oral tamoxifen and moistened misoprostol administered vaginally was superior to that of placebo and moistened misoprostol administered vaginally for elective termination of early pregnancies.A clinical trial was conducted with a study group of 150 healthy women with pregnancies of </=56 days gestational age who desired pregnancy termination. Subjects were randomized to ingest either 20 mg of tamoxifen (group 1) or placebo (group 2) twice daily for 1 day, followed 48 h later by vaginal administration of 800 micrograms of saline-moistened misoprostol. This dose of misoprostol was repeated 24 h later and 8 days later if an abortion had not occurred. The main outcome measures were incidence of complete abortion, hemoglobin levels, duration of vaginal bleeding, and incidence of side effects. Complete abortion occurred in 709 (93.3%) in group 1 and 68 (90.7%) in group 2. There were no differences in either group between earlier (</=49 days) and later (50-56 days) gestations. The mean duration of uterine bleeding was 7.9 days and 8.2 days in group 1 and group 2, respectively. In group 1, 94.3% who aborted bled for <14 days, and in group 2, 95.6%. No subject required a blood transfusion. There were no significant differences in side effects between the two groups. These data suggest that pretreatment with tamoxifen is not necessary when using moistened vaginal misoprostol for abortion of pregnancies of </=56 days of gestation.

Abortifacient Agents, Nonsteroidal↗