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PubMed1992

Intrauterine progestin induces continuous insulin-like growth factor-binding protein-1 production in the human endometrium.

The effect of local intrauterine progestin on endometrial insulin-like growth factor-binding protein-1 (IGFBP-1) production was studied in 60 women using a levonorgestrel-releasing intrauterine device (IUD). Intrauterine progestin was a potent stimulator of stromal cell IGFBP-1 production, with 97% of endometrial specimens showing positive staining by immunohistological methods. After 5 yr or more of intrauterine progestin exposure, 100% (n = 20) of the tissues remained strongly positive for IGFBP-1. The IGFBP-1 content in endometrial tissue homogenates reached values as high as 10 micrograms/mg protein when measured by immunoradiometric assay. In contrast to the continuous endometrial IGFBP-1 production induced by local progestin, no such effect could be found in endometria from subjects with sc progestin-releasing implants or copper IUDs. Although the levonorgestrel-releasing IUD had a striking effect on local endometrial IGFBP-1 production, it had no effect on serum IGFBP-1 levels. By Western ligand blot analysis, the domainating IGF-binding species in endometria exposed to intrauterine progestin was of 28K mol wt, corresponding to IGFBP-1, whereas no IGFBP species of 31-43K, corresponding to IGFBP-2 or IGFBP-3, were detected.

Adult↗

PubMed1989

Progestin increases gene transcription and messenger ribonucleic acid stability of fatty acid synthetase in breast cancer cells.

The cDNA clone (Pg8) corresponding to the 3'-end of fatty acid synthetase (FAS) mRNA is one of the few probes to study in cell lines the mechanism by which an endogenous gene is regulated by progestins. The steady-state level of FAS mRNA is known to be increased by the synthetic progestin R5020 in the human breast cancer cell line MCF7. We show here that it is also increased in another progesterone-receptor-positive cell line T47D but not in progesterone-receptor-negative cell lines BT20, MDA-MB231, and HBL100. In R5020-treated MCF7 cells, the FAS mRNA concentration increased with cell density. Protein synthesis inhibitors did not abolish progestin induction of FAS suggesting a primary effect of the hormone. In vitro nuclear run-on transcription assays showed that the FAS gene transcription rate was increased about 4-fold by progestin. This stimulation of transcription was detectable 30 min after addition of R5020 and was maximal after 4 h, but could not totally account for the total increase in the mRNA steady state level. Chase experiments in the presence of Actinomycin D or Cordycepin showed that progestin also increased the half-life of FAS mRNA from 6-9 h to 24-33 h. We conclude that progestin stimulates the FAS concentration both by increasing the transcription rate of the gene and by stabilizing the mRNA.

Blotting, Northern↗

PubMed1998

Calcium/calmodulin kinase inhibitors and immunosuppressant macrolides rapamycin and FK506 inhibit progestin- and glucocorticosteroid receptor-mediated transcription in human breast cancer T47D cells.

The effects of immunosuppressants and inhibitors of specific calcium/calmodulin kinase (CaMK) of types II and IV on progestin/glucocorticosteroid-induced transcription were studied in two human stably transfected breast cancer T47D cell lines. The lines contain the chloramphenicol acetyl transferase (CAT) gene under control either of the mouse mammary tumor virus promoter (T47D-MMTV-CAT), or the minimal promoter containing five glucocorticosteroid/progestin hormone response elements [T47D-(GRE)5-CAT]. Progestin- and triamcinolone acetonide (TA)-induced CAT gene expression was inhibited in a dose-dependent manner in both lines by preincubation with rapamycin (Rap) and, to a lesser extent, with FK506, but not with cyclosporin A. CaMK II and/or IV inhibitors KN62 and KN93 also inhibited progestin- and TA-stimulated transcription in both lines. None of these drugs had any effect on basal transcription. The antagonist RU486 inhibited all the effects of both progestin and TA, suggesting that progesterone receptor (PR)-, as well as glucocorticosteroid receptor (GR)- mediated transactivation are targets of immunosuppressants and CaMKs in T47D cells. Indeed, Northern analysis showed that Rap, KN62, and, to a lesser degree, FK506 inhibited progestin stimulation of Cyclin D1 mRNA levels, but not those of the non-steroid-regulated glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene. Addition of Rap or KN62 after exposure of cells to progesterone agonist Org 2058 had no effect on induction of CAT activity. Taken together, these data indicate that Rap and FK506, as well as CaMK inhibitors, inhibit steroid-induced activities of exogenous, as well as of some endogenous, steroid receptor-regulated genes by a mechanism preceding hormone-induced receptor activation. Rap appeared to stabilize a 9S form of [3H]Org 2058-PR complexes isolated from T47D (GRE)5CAT cell nuclei. By contrast, the progesterone receptor (PR) was isolated from cells treated with KN62 as a 5S entity, undistinguishable from the 5S PR species extracted from cells treated with progestin only. The nuclear 9S-[3H]Org2058-PR resulting from cells exposed to Rap, contained, in addition to the heat shock proteins of 90 kDa and 70 kDa (hsp90 and hsp70), the FK506-binding immunophilin FKBP52 but not FKBP51, although the latter was part of unliganded PR heterocomplex associated with hsp90. These results suggest that Rap and KN62 act upon the PR by distinct mechanisms, with only Rap impeding progestin-induced PR transformation. FKBP51 appeared to dissociate from the receptor heterocomplex, but not from hsp90, after hormone binding to PR in vitro and in vivo, whether in the presence or not of Rap and KN62. Immunoprecipitation experiments distinguished two PR- and glucocorticosteroid (GR)-associated molecular chaperone complexes, containing hsp90 and hsp70 and FKBP52 or FKBP51. Another complex identified in T47D cytosol contained hsp90 and the cyclosporin A-binding cyclophilin of 40 kDa, CYP40, but not hsp70, PR, or GR. These observations support the concept that FKBP51 and FKBP52 can act as regulators of Rap and FK506 activity upon PR and GR-mediated transcription, a mechanism that could be also regulated by type II and/or type IV CaMKs.

Animals↗

PubMed1985

Progestin receptor in the thymus of ovariectomized immature rats.

By using the synthetic progestin promegestone (R5020), the location and characteristics of progestin receptors in the thymic cytosols from immature ovariectomized oestrogen-treated rats were determined. Tritiated promegestone bound to the cytosol with high affinity (dissociation constant (Kd) = 2.0 +/- 0.3 nmol/l; promegestone greater than progesterone greater than oestradiol greater than corticosterone testosterone) and low capacity (number of binding sites (Bmax) = 143.0 +/- 13.5 fmol/mg protein). These values were appropriate for progestin receptors. However, an extremely high dose of dexamethasone (10 mumol/l; 1000-fold excess over [3H]promegestone) slightly inhibited the specific binding. Progestin receptors were predominantly located in the reticuloepithelial (RE)-cell fraction, with few in the thymocyte T-cell fraction. The receptor level was raised (24.9 +/- 11.3 (S.E.M.) to 143.0 +/- 13.5 fmol/mg protein) with increased doses of oestrogen (0-30 micrograms) administered in vivo. Using sucrose density gradient ultracentrifugation it was found that the thymic progestin receptor had a sedimentation coefficient of 9S under low-salt conditions. These results clearly suggest that the thymus of the immature female rat contains a specific progestin receptor which is mainly located in the RE cells.

Animals↗

PubMed1997

Effect of age and pattern of gain on induction of puberty with a progestin in beef heifers.

Crossbred heifers (n = 75) fed for rapid (R; .82 kg/d) or slow-then-rapid (SR; .41 kg/d for 90 d then .82 kg/d) postweaning gain were used to examine the effects of age or pattern of gain on induction of puberty by a progestin. At 9.5, 11.0, and 12.5 mo of age, 12 prepuberal heifers from each growth treatment received progestin (a 6-mg Norgestomet implant for 10 d) or control treatments. Induction of puberty, LH secretory profiles, and ovarian follicular characteristics were assessed in Norgestomet-treated and control heifers. Body weights of R heifers were greater (P < .01) than those of SR heifers at all ages. At 12.5 mo, more Norgestomet-treated heifers exhibited a puberal estrus within 5 d after implant removal compared with controls (82% vs 9%, respectively), but Norgestomet did not induce puberty at 9.5 or 11 mo of age (progestin x age, P < .05) in heifers of either gain pattern. Norgestomet increased (P < .01) LH pulse frequency at all ages, whereas Norgestomet increased only mean LH concentrations at 12.5 mo of age (progestin x age, P < .03). Norgestomet treatment altered (P < .01) ovarian follicular characteristics at all ages. Gain pattern did not affect (P > .1) LH secretory profiles, ovarian characteristics, or induction of puberty by Norgestomet. We conclude that progestins induce puberty by hastening the normal cascade of endocrine and ovarian events associated with spontaneous puberty. Furthermore, age, but not pattern of gain, seems to be the critical factor influencing the efficacy of progestins to induce puberty in heifers.

Aging↗

PubMed1991

Transforming growth factor gene expression in human endometrial adenocarcinoma cells: regulation by progestins.

In an attempt to understand the antiproliferative effects of progestins in endometrial cancer, we have examined the effects of the potent progestin, medroxyprogesterone acetate (MPA), on the cell proliferation and the expression of transforming growth factor (TGF) alpha and beta genes in human endometrial adenocarcinoma cell lines. The two cell lines used were Ishikawa, var 1, and HEC-50. In addition, the effects of exogenous TGF-alpha and anti-epidermal growth factor (EGF) receptor monoclonal antibody on cell proliferation were determined. Incubation of both cell lines with MPA resulted in a time- and dose-dependent inhibition of cell proliferation. Half-maximal growth inhibition was observed at 0.6 nM. In Ishikawa cells, the relative abundance of TGF-alpha was significantly reduced by MPA. A significant decrease in TGF-alpha mRNA was apparent 6 h after exposure to MPA and a further decrease was seen 12-24 h after addition of the progestin. The concentration of TGF-alpha immunoreactivity in conditioned medium of MPA-treated cells was also significantly reduced compared to control cultures. MPA had no effect on TGF-alpha expression by HEC-50 cells. EGF mRNA was not detected by Northern blot analysis in either cell type. MPA had no significant effect on EGF receptor mRNA abundance but resulted in a small increase in EGF receptor number in Ishikawa cells. Anti-EGF receptor monoclonal antibody (0.6-6 nM) inhibited Ishikawa cell growth but had no effect on HEC-50 cell proliferation. Exogenous TGF-alpha stimulated proliferation of both cell lines, but Ishikawa cells were significantly more sensitive to exogenous TGF-alpha than HEC-50 cells. Furthermore, TGF-alpha could reverse the growth inhibitory effects of MPA on Ishikawa cells. A decrease in TGF-beta mRNA abundance was also observed in MPA-treated Ishikawa and HEC-50 cells. This effect was of small magnitude, variable, and only observed after prolonged exposure to MPA. These observations are consistent with the hypothesis that the antiproliferative effects of progestins on Ishikawa cells are mediated by decreased expression and autocrine action of TGF-alpha. Since similar growth inhibition is also seen in the HEC-50 cells in which progestins have no effect on TGF-alpha expression, additional mechanisms are likely to be involved in the antiproliferative effects of progestins in human endometrial cancer.

Antineoplastic Agents↗

PubMed1988

Endometrial histology and bleeding patterns in menopausal women treated with estrogen and continuous or cyclic progestin.

Thirty-six postmenopausal women were randomized to three groups in a double-blind, prospective study. All were treated for three months with conjugated estrogens (Premarin), 0.625 mg daily, and three different doses of a progestin (Provera), 2.5 mg daily, 5 mg daily or 5 mg during the last 12 days of a 28-day cycle. We found that the endometrium was maintained in an inactive phase in 100% of the women given continuous daily progestin but in only 25% of those given cyclic progestin. Bleeding occurred in 100% of subjects given cyclic progestin and in 50% of those given continuous progestin; however, bleeding episodes diminished with time in those on continuous progestin. A hormonal regimen that leads to reduced or absent bleeding and an inactive endometrium is preferable for postmenopausal women if estrogen therapy is to be used for the long term after menopause.

Antineoplastic Agents↗

PubMed1986

Prediction of clinical outcome with estrogen and progestin receptor concentrations and their relationships to clinical and histopathological variables in endometrial cancer.

Concentrations of cytosol estrogen (ERC) and cytosol progestin (PRC) receptors were assayed in malignant tissue specimens of 230 patients with endometrial cancer, and those of nuclear estrogen and nuclear progestin receptors, and 17 beta-hydroxysteroid dehydrogenase activities in about 100 specimens. Endometrial cancer was at an early stage in 205 and advanced in 25 patients. As a supplement to surgical and radiation therapy, all patients received p.o. medroxyprogesterone acetate (100 mg a day) for 2 years. The follow-up time varied from 12 to 96 months (median, 42 months). Concentrations of ERC, PRC, nuclear estrogen, and nuclear progestin receptors in endometrial cancer tissue were significantly lower in clinical stages III-IV than in clinical stage I. In clinical stage I, ERC and PRC appeared in significantly lower concentrations in anaplastic than in moderately and well differentiated malignancies. The concentrations of these receptors were increased in obese patients, and the activity of 17 beta-hydroxysteroid dehydrogenase was increased in patients younger than 50 years, suggesting that endogenous female steroid hormones modify the pattern of female steroid receptors in malignant endometrium. In clinical stage I, 13 of 153 patients with adequate therapy contracted a recurrent disease. Poor prognosis was predicted by anaplastic structure of the malignancy (P less than 0.001), low tissue concentrations (0-30 fmol/mg protein) of ERC alone (P = 0.006), PRC alone (P = 0.010), and ERC and PRC simultaneously (P = 0.004). All 101 patients who simultaneously had ERC and PRC in concentrations higher than 30 fmol/mg protein remained disease free for 2 years, whereas all recurrences in patients with receptor-poor tumors appeared during the 2 years of medroxyprogesterone acetate treatment. In clinical stage II, with 30 patients, no prognosis indicators predicted the clinical outcome, whereas in clinical stages III + IV, with 25 patients, low ERC concentrations were associated with a worsened prognosis (P = 0.045). Conclusively, cytosol and nuclear estrogen and nuclear progestin receptor concentrations and 17 beta-hydroxysteroid dehydrogenase activity give valuable information about the endocrine associations in endometrial cancer. Cytosol estrogen and cytosol progestin receptors appeared to be useful predictors of recurrent disease. They also have the potential to distinguish between patients expected to benefit from adjuvant progestin therapy and those expected to be unresponsive to the same treatment.

Aged↗

PubMed1987

Fatty acid synthetase and its mRNA are induced by progestins in breast cancer cells.

The growth of hormone-dependent breast cancer cell lines (MCF7 and T47D) is inhibited in vitro by progestins which also induce several proteins. We have cloned cDNA sequences corresponding to one of them, a 250-kDa protein, and have shown that the corresponding mRNA is also rapidly induced by progestins (Chalbos D., Westley B., May F.E.B., Alibert C., and Rochefort H. (1986) Nucleic Acids Res. 14, 965-982). We show here that the 250-kDa protein is very similar, if not identical, to fatty acid synthetase: fatty acid synthetase is regulated to the same extent by progestins, the 250-kDa protein is specifically immunoprecipitated by antibodies to fatty acid synthetase, and fatty acid synthetase covalently labeled by [14C]pantothenate is immunoprecipitated by antibodies to the 250-kDa protein. The induction of fatty acid synthetase by progestin in cancer cells thus provides another model for studying the mechanism regulating steroid transcription in human cells. Since fatty acid synthetase regulation by progestins appears to be the opposite in cancer and normal mammary cells, this observation may also be a clue for understanding the role of progestins in mammary carcinogenesis.

Antibodies↗

PubMed1985

Histopathologic correlations of estrogen and progestin receptor protein in epithelial ovarian carcinomas.

One hundred thirteen primary epithelial ovarian cancers were analyzed for estrogen and progestin receptor content and the results compared with multiple histologic parameters (grade, necrosis, fibrosis, lymphocyte infiltration, mitoses, tumor giant cells, psammoma bodies, stroma). Grade 4 cancers had a statistically greater likelihood of containing estrogen receptors (P = .03) than did lower grade cancers. However, grade 3 tumor samples containing abundant (3+ and 4+) mitoses had a significantly greater number of estrogen receptor negative cancers (P = .01) than did cancers containing none to moderate (0-2+) mitoses. The only histologic parameter that demonstrated any statistically significant association with progestin receptor content was the presence of lymphocyte infiltration. Samples demonstrating moderate (2+ and 3+) lymphocyte infiltration had a significantly (P = .005) greater chance of being progestin receptor negative than cancers containing none to minimal (0 to 1+) lymphocyte infiltration. This study suggests that estrogen and progestin receptor content of epithelial ovarian cancers is associated with grade and mitoses (estrogen receptor) and lymphocyte infiltration (progestin receptor). With the exception of these relationships, the estrogen and progestin receptor content of ovarian cancers appears independent of all of the histologic parameters examined.

Adult↗

PubMed1980

Estrogen, androgen, glucocorticoid, and progesterone receptors in progestin-induced regression of human breast cancer.

A study was made of basic mechanisms involved in regression of breast cancer exposed to high levels of synthetic progestins. The possibility that progestins act on breast cancer by way of the progesterone receptor mechanism and subsequent increase of estradiol 17 beta-dehydrogenase activity could not be confirmed in this investigation. It is demonstrated that the progestins megestrol acetate and medroxyprogesterone acetate are strong competitors for steroids which bind specifically to androgen, glucocorticoid, and progesterone receptors, indicating that the progestins are able to bind to these receptors with high affinity. In contrast, these progestins do not compete with estradiol for estrogen receptor binding. In 34 patients with progressive metastatic breast cancer, results of receptor studies have been correlated with clinical response during treatment with megestrol acetate. Statistically, regressions were significantly associated with tumors containing large amounts of androgen receptors. Clinical correlation with the quantities of glucocorticoid receptor was weak, while such correlations with estrogen and progesterone receptors were absent. However, we did demonstrate relationships between the quantities of the various receptors in breast cancer. Tumors containing a large amount of androgen receptors also generally contain estrogen receptors. It might be that a favorable response to progestins is confined to the group of patients with hormone-responsive breast cancers, as such characterized by the presence of estrogen receptors, and that within this group the actual androgen receptor levels determine response.

Breast Neoplasms↗

PubMed1994

Quantitative and qualitative changes in lipids, lipoproteins, apolipoprotein A-I, and sex hormone-binding globulin due to two doses of conjugated equine estrogen with and without a progestin.

OBJECTIVE: To determine whether the quantitative and qualitative effects on lipoproteins differ between two doses of conjugated equine estrogen before and after progestin administration. METHODS: We randomized 103 postmenopausal women into a control group and into two groups receiving either 0.625 mg or 1.25 mg of conjugated equine estrogen for 4 months and then the same estrogen dose plus cyclic medroxyprogesterone acetate for 8 months. RESULTS: Both estrogen doses similarly lowered (P < .01) low-density lipoprotein (LDL) cholesterol and raised (P < .01) high-density lipoprotein (HDL) cholesterol, apolipoprotein A-I, triglyceride levels of all lipoproteins, and sex hormone-binding globulin capacity. Cyclic addition of the progestin reduced HDL cholesterol (P < .01) and apolipoprotein A-I (P < .05), but not LDL cholesterol in either estrogen group. A greater lowering of HDL cholesterol (P < .05) in response to the progestin was seen with the 0.625-mg dose of estrogen. Estrogen-induced triglyceride enrichment of HDL and LDL was not reversed by the progestin. CONCLUSION: The only significant quantitative difference in lipoprotein levels between the doses of conjugated equine estrogen before or after administration of medroxyprogesterone acetate was a greater decline in HDL cholesterol levels with the lower dose after 4 months of the progestin. This difference was not sustained over time. There were no differences between doses in the estrogen-induced triglyceride enrichment of lipoproteins, and these qualitative changes were not affected by the progestin.

Adult↗

PubMed1998

Effects of two progestin-only contraceptives, Depo-Provera and Norplant-II, on the vaginal epithelium of rhesus monkeys.

The objective of this study was to determine whether progestin-only contraceptives induce thinning of the vaginal epithelium in nonhuman primates. Eight intact rhesus monkeys (four per group) were treated with either a single intramuscular injection of 30 mg of Depo-Provera or a subcutaneous insertion of Norplant-II (2 x 75 mg rods; day 0). Norplant-II rods were removed 90 days after insertion. Vaginal biopsies were obtained during a pretreatment menstrual cycle and following treatment on days 10, 30, 60, 118, and 146. Formalin-fixed vaginal biopsies were evaluated for epithelial thickness and the degree of keratinization. The circulating levels of estradiol, progesterone, medroxyprogesterone acetate (MPA), or levonorgestrel (LNG) were monitored throughout the study by specific radioimmunoassays. Circulating levels of estradiol and progesterone confirmed the stage of the menstrual cycle in which pretreatment biopsies were obtained. Following treatment with Depo-Provera, serum levels of MPA increased to 2.3 +/- 0.6 ng/ml (x +/- SE, n = 4) within 24 hr. Serum levels of MPA were maximal on day 14 (5.5 +/- 0.9 ng/ml), dropped below 1 ng/ml by day 50, and were nondetectable by day 70. Circulating levels of LNG were elevated 24 hr after insertion of Norplant-II (5.8 +/- 3.0 ng/ml), peaked on day 2 (7.6 +/- 4.2 ng/ml), remained between 1.4 and 6.2 ng/ml from days 14 to 90, and were nondetectable by day 118, the first serum sample after removal of Norplant-II. There were no significant differences (p > 0.05) in the epithelial thickness (microm), number of epithelial cell layers, or type of epithelium present in vaginal biopsies obtained during the follicular or luteal phases of the pretreatment menstrual cycle. Conversely, a pronounced effect of progestin treatment was observed on the vaginal epithelium. There were no significant differences (p > 0.05) between the two progestin treatment groups, but a significant effect (p < 0.05) over time was observed (two-way ANOVA). Compared with pretreatment menstrual cycle controls, the vaginal epithelial thickness was decreased (p < 0.05) by day 30 or 60 following Norplant-II insertion or Depo-Provera injection, respectively. The number of epithelial cell layers was also decreased (p < 0.05) on days 30 and/or 60 in progestin-treated monkeys compared with pretreatment control cycles. Following removal of Norplant-II or metabolic excretion of MPA, the vaginal epithellium regenerated and the thickness was no longer different (p > 0.05) from the pretreatment control cycle. These data demonstrate that progestin-only contraceptives induced thinning of the vaginal epithelium in rhesus monkeys, and this effect was rapidly reversible following physical or metabolic removal of the progestin.

Animals↗

PubMed1998

Estradiol inhibits LDL oxidation: do the progestins medroxyprogesterone acetate and norethisterone acetate influence this effect?

Estrogen replacement therapy in postmenopausal women must be combined with progestin to avoid endometrial cancer. However, progestin addition could antagonize cardioprotective effects of estradiol. Therefore we investigated the effect of the two most commonly used progestins--medroxyprogesterone acetate (progesterone-derivative) and norethisterone acetate (nortestosterone-derivate)--alone and in combination with 17 beta-estradiol on copper-mediated oxidation of low density lipoprotein (LDL). Whereas 17 beta-estradiol alone inhibited the onset of LDL oxidation at the concentrations 0.5, 1.0, 5 and 10 microM, the progestins alone did not demonstrate any significant effect. In the estrogen-progestin combinations of 0.5 microM 17 beta-estradiol with 0.5, 1.0, 5 and 10 microM progestin, respectively, the estradiol effect was not changed. These results suggest that medroxyprogesterone acetate as well as norethisterone acetate do not counteract the beneficial effect of 17 beta-estradiol on LDL oxidation when used in hormone replacement therapy.

Drug Interactions↗

PubMed1988

The varying effects of progestins on lipid levels and cardiovascular disease.

A recent study at George Washington University Lipid Research Clinic compared three oral contraceptives containing different progestins and found that increases in total cholesterol, triglycerides, and apoprotein. All were not progestin related. Other effects, however, were apparently dependent on the type of progestin, with the androgenically potent agent dl-norgestrel causing dramatic increases in low-density lipoprotein (LDL)-cholesterol and the ratio of low-density to high-density lipoprotein (HDL) and decreases in HDL, particularly HDL2, and apoprotein Al. Reductions in HDL2 and increases in the LDL/HDL ratio are strongly associated with the development of atherosclerosis. In a study of postmenopausal women receiving hormone replacement therapy, estrogen alone was compared with estrogen plus dl-norgestrel. In contrast to the findings of the previous study, norgestrel lowered LDL and produced less substantial decreases in HDL and HDL2. Thus, although an antiestrogenic effect was evident, it cannot be assumed that the changes associated with progestin-containing oral contraceptives will automatically occur when lower doses of progestin are used in hormone replacement therapy.

Adolescent↗

PubMed1995

The androgenicity of progestins.

All steroid hormones are structurally similar, but relatively minor differences cause profound alterations in biochemical activity. The 21-carbon series (pregnane nucleus) includes the corticoids and the true progestins (e.g., medroxyprogesterone acetate). The 19-carbon series (androstane nucleus) includes all the androgens, among them the progestins used in most oral and parenteral contraceptives. The removal of carbon 19 from testosterone changes the major hormonal effect from androgenic to progestogenic, but these "19-nor" steroids retain varying degrees of androgenic activity. (They can also have limited estrogenic activity, but this is insignificant at the low doses used for contraception.) Some of the 19-nortestosterone progestins are metabolized to other compounds (e.g., norethynodrel, ethynodiol diacetate, and lynestrenol to norethindrone), and some (levonorgestrel, desogestrel) are active unchanged. The lingering androgenic effects of 19-nor progestins are dose-related, opposed by estrogen, and are manifested metabolically (e.g., glucose tolerance, lipoprotein synthesis) and symptomatically (e.g., acne, weight gain). The effect of 19-nortestosterones on lipoproteins prompted the development of less androgenic compounds, but the obvious benefit of the new progestins (desogestrel, gestodene, norgestimate) is a reduction in the symptoms associated with the androgenicity of the older compounds. Mitigation of androgenic effects on lipoprotein and carbohydrate metabolism could have long-term benefits, especially for women who are at risk of arteriosclerotic vascular disease; however, these effects remain to be epidemiologically demonstrated.

Androgens↗

PubMed1998

Effect of oral contraceptive progestins on serum copper concentration.

OBJECTIVES: Recent epidemiologic studies have shown an increased mortality from cardiovascular diseases in people with higher serum copper levels. Even though higher serum copper concentration in women using oral contraceptives is well known, there is still uncertainty about the influence of newer progestin compounds in oral contraceptives on serum copper concentration. This issue is of particular interest in the light of recent findings of an increased risk of venous thromboembolism in users of oral contraceptives containing newer progestins like desogestrel compared to users of other oral contraceptives. DESIGN: Cross-sectional epidemiologic study. Examinations included a detailed questionnaire on medical history and lifestyle factors, a seven day food record, and blood samples. SETTING: National health and nutrition survey among healthy people living in private homes in West Germany in 1987-1988. SUBJECTS: Nonpregnant and nonlactating women aged 18-44 y (n = 610). RESULTS: Overall, the use of oral contraceptives was positively associated with serum copper concentration in by bi- and multivariable linear regression models with log-transformed values of serum copper concentration as dependend variable and oral contraceptive preparations and potential confounding variables as independent variables. Serum copper concentration in women using oral contraceptives varied more strongly by different progestin compounds than by estrogen contents. The highest increase of serum copper was seen in women using oral contraceptives containing antiandrogen progestins (55%; 95% CI: 37-76%), followed by desogestrel (46%; 95% CI: 36-56%), norethisteron/lynestrenol (42%; 95% CI: 29-57%), and levonorgestrel (34%; 95% CI: 24-45%). CONCLUSION: While elevated serum copper concentration was found in users of all types of oral contraceptives, elevation was more pronounced among women taking oral contraceptives with antiandrogen effective progestins like antiandrogens or third generation oral contraceptives containing desogestrel. Further investigation is required to shed light on the possible role of high serum copper concentration in increasing cardiovascular or thrombotic risk of women using oral contraceptives.

Adolescent↗

PubMed1991

Subdermal progestin implant contraception.

Sustained-release progestin contraceptives are a new approach to meeting a worldwide need for more effective and acceptable birth control. These contraceptive systems provide low, stable levels of synthetic progestins for periods of months to several years. Unlike earlier injectable and oral contraceptives, they do not cause peaks in progestin levels beyond those required for effective contraception, nor do they employ estrogens. For these reasons, sustained-release progestin systems are without some of the health risks attributed to birth control pills, and they are more effective, as well as easy to use, and completely reversible. They share common side effects, the most frequent of which is irregular menstrual bleeding caused by the erratic shedding of hypotrophic endometrium. Despite this and other minor side effects, most users find the sustained-release systems acceptable alternatives to other methods of contraception. Permanent or biodegradable subdermal implants, injections, intrauterine and intracervical devices, and vaginal rings are all employed as delivery systems for contraceptive progestins. The Norplant (Wyeth Ayerst, Radnor, PA) system, consisting of six silastic tubes filled with levonorgestrel and implanted under the skin, was recently approved by the US Food and Drug Administration and is already used by more than a half million women worldwide. The other sustained-release systems are in various stages of development, at least several years away from general use. When these new methods complete clinical trials, women will be able to choose from among implants, injections, or pellets with various durations of action, all providing convenient, highly effective contraception with low risk to health.

Biodegradation, Environmental↗