Effect of prednisolone on serum and follicular fluid androgen concentrations in women with polycystic ovary syndrome undergoing in-vitro fertilization.
(9/967)
Increased androgen concentrations are thought to be detrimental to oocyte quality and reproductive potential. Adjuvant treatment with glucocorticoids has been tried to suppress androgens in women undergoing infertility treatment. In the present study 20 infertile women with polycystic ovary syndrome were prospectively randomized in a placebo-controlled study to receive either placebo or prednisolone 10 mg at night, during standard in-vitro fertilization (IVF) treatment. Serum samples for assays of gonadotrophins, steroids and sex hormone-binding globulin (SHBG) were collected before treatment, at down-regulation, and at oocyte retrieval. Up to five follicles in each ovary were analysed separately regarding follicular fluid and oocytes, the rest according to the clinic's routines. In the placebo group, serum dehydroepiandrosterone (DHEA) and dehydroepiandrosterone-sulphate (DHEA-S) did not change between down-regulation and oocyte retrieval, whereas adjuvant prednisolone resulted in a significant decrease. In follicular fluid, adjuvant prednisolone resulted in significantly lower concentrations of DHEA-S as compared to placebo, no other significant differences were found. No significant differences were found in embryo characteristics or pregnancy rates between the groups. (+info)
Chemoprevention of rat prostate carcinogenesis by early and delayed administration of dehydroepiandrosterone.
(10/967)
Two in vivo bioassays were conducted to evaluate the efficacy of dehydroepiandrosterone (DHEA) as an inhibitor of prostate carcinogenesis in rats. Prostate adenocarcinomas were induced in male Wistar-Unilever rats by a sequential regimen of cyproterone acetate and testosterone propionate, followed by a single i.v. injection of N-methyl-N-nitrosourea (MNU) and chronic androgen stimulation. In the first experiment, DHEA (1000 or 2000 mg/kg diet) was administered continuously to rats beginning 1 week before MNU exposure. In the second experiment, continuous administration of DHEA (2000 mg/kg diet) was begun either 1 week before, 20 weeks after, or 40 weeks after MNU exposure. Controls received basal diet without added DHEA. Studies were terminated at 13 months after MNU administration, and prostate cancer incidence was determined by histopathological evaluation of step sections of accessory sex glands. In the first study, continuous dietary administration of DHEA beginning 1 week before MNU resulted in a dose-related inhibition of prostate cancer induction. In the second experiment, comparable reductions in prostate cancer incidence were observed in groups exposed to DHEA beginning 1 week before, 20 weeks after, and 40 weeks after carcinogen exposure. These data demonstrate that nontoxic doses of DHEA confer significant protection against prostate carcinogenesis in rats. The efficacy of delayed administration of DHEA suggests that the compound confers protection against later stages of prostate cancer induction and can suppress the progression of existing preneoplastic lesions to invasive disease. (+info)
Should dehydroepiandrosterone replacement therapy be provided with glucocorticoids?
(11/967)
Adrenocorticotrophic hormone (ACTH) induces the concomitant secretion of glucocorticoids (GC) and dehydroepiandrosterone (DHEA) from the adrenal cortex. Whereas GC are catabolic, DHEA is anabolic. Long-term GC administration may result in some deleterious side-effects, such as muscular weakness, atrophy and necrosis, diabetes, fattiness, osteopenia, osteoporosis and avascular necrosis and susceptibility to infections. DHEA ameliorates some deleterious effects of GC, such as diabetes, amino acid deamination, fattiness, hypertension and susceptibility to viraemia. By its anabolic effects in muscles, bones and endothelium, DHEA may diminish the severity of GC-induced myopathy, osteopenia, osteoporosis and avascular necrosis. The natural concomitant secretion of DHEA with GC probably enables the latter to protect the body from ill-effects of stress without exerting their deleterious potency. DHEA secretion diminishes during aging and severe or chronic diseases such as rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE). Anti-inflammatory and immunosuppressive effects of GC and androgens, including DHEA, are now well established. On the other hand, administration of GC inhibits ACTH secretion, involutes the adrenal cortex and results in further DHEA deficiency, particularly harmful in chronic autoimmune diseases (i.e. RA, SLE). Therefore, the deleterious side-effects of chronic administration of GC emerges from both their direct catabolic activity and the suppression of DHEA production. Whereas, in males, most androgens come from the testes, in females, under GC supplementation, DHEA deficiency leads to nullification of the androgen-dependent anabolism, leaving them exposed to the GC-catabolic effects to a larger extent. The viewpoint presented here claims that under chronic GC supplementation, DHEA replacement therapy may reduce damage caused by GC administration. (+info)
Protective effect of dehydroepiandrosterone against lipid peroxidation in a human liver cell line.
(12/967)
OBJECTIVE: Dehydroepiandrosterone (DHEA) is a widely studied steroid hormone with multi-functional properties. Reports suggest that some of the many activities of DHEA are due to its protective effect against lipid peroxidation. Nevertheless, the antioxidant properties of DHEA are still the subject of debate. The aim was to evaluate whether its two opposed effects on lipid peroxidation reported in the literature may be dependent on schedule and doses used. METHODS: Chang liver cells, a line derived from normal human liver, were grown in media containing either no steroids (control) or DHEA at concentrations ranging from 0.1 micromol/l to 50 micromol/l. At specific times, cultures were halted and cells received a pro-oxidant stimulus (cumene (CuOOH) 0.5 mmol/l), at which time cell viability (by trypan blue staining and lactate dehydrogenase (LDH) release) and thiobarbituric acid reactive substances (TBARS) concentration (spectrophotometrical assay) were evaluated. RESULTS: At concentrations ranging from 0.1 micromol/l to 1 micromol/l, DHEA protects Chang liver cells against lipid peroxidation and/or death induced by cumene. This effect disappears if the concentration is increased to 10 micromol/l; at higher concentrations (50 micromol/l) a pro-oxidant/cytotoxic effect of DHEA appears. CONCLUSIONS: DHEA exhibits two opposed effects on lipid peroxidation; depending on its concentration it acts either to limit or to induce oxidative stress. The threshold concentration at which the pro-oxidant activity of DHEA prevails is not far in excess of that having an antioxidant effect. Either effect of DHEA on lipid peroxidation is only evident after a 'lag-phase'. (+info)
Dexamethasone in resting and exercising men. II. Effects on adrenocortical hormones.
(13/967)
This study presents the reactions of adrenocorticosteroids (cortisol and aldosterone) and sex steroids [testosterone, androstenedione, and dehydroepiandrosterone and its sulfate (DHAS)] 1) to a dexamethasone (Dex) treatment, which is expected to lower steroid levels via the ACTH blockade, and 2) to an exercise bout at maximal O(2) consumption, which is expected to increase steroid production via ACTH stimulation. Consistent with the decrease in ACTH, all steroids except testosterone reacted negatively to Dex, independently of the dose (0.5 and 1.5 mg administered twice daily for 4.5 days). After exercise, plasma ACTH rose to 600% of basal value, resulting in a significant increase in aldosterone and adrenal androgens, but cortisol and DHAS were unaffected. This apparently surprising result can be explained by differences in peripheral metabolism: a theoretical calculation predicted that after 15 min the increase in hormone concentration may only reach 12% for cortisol and 2% for DHAS. For cortisol and adrenal androgens, assays were carried out using plasma and saliva. The consistent results obtained from the two matrices allow us to consider salivary assays as a useful tool for steroid abuse detection. (+info)
DHEA: panacea or snake oil?
(14/967)
OBJECTIVE: To review the evidence that supplementation with dehydro-3-epiandrosterone (DHEA) is beneficial in aging, cardiovascular disease, immune function, and cancer. METHODS: English-language literature search using MEDLINE with subject headings DHEA, adrenal steroids, and androgens. QUALITY OF EVIDENCE: Although some randomized, double-blind, placebo-controlled trials have been conducted, most of the evidence supporting use of DHEA for any disease state is of poor quality and consists of case reports and case-control and open-label clinical trials. MAIN MESSAGE: Dehydro-3-epiandrosterone is available as a health food supplement and is touted as being beneficial for a variety of diseases. It might be beneficial for improving someone's sense of well-being; minor improvements in body composition have been noted for men only. No consistent relationship has been demonstrated between levels of DHEA and risk of cardiovascular disease, breast cancer, or immune function. Insufficient evidence exists to support using DHEA for acquired immune deficiency syndrome. High levels of DHEA are associated with adverse effects, such as increased risk of breast and ovarian cancer at certain ages and reduced levels of high-density lipoprotein cholesterol. CONCLUSIONS: Current enthusiasm for using DHEA as a panacea for aging, heart disease, and cancer is not supported by scientific evidence in the literature. Given the potentially serious adverse effects, using DHEA in the clinical setting should be restricted to well-designed clinical trials only. (+info)
Dehydroepiandrosterone suppresses the elevated hepatic glucose-6-phosphatase and fructose-1,6-bisphosphatase activities in C57BL/Ksj-db/db mice: comparison with troglitazone.
(15/967)
The effect of dehydroepiandrosterone (DHEA) on the hepatic and muscle glucose metabolizing enzymes and on blood glucose were investigated in insulin-resistant diabetic C57BL/KsJ-db/db mice and their heterozygote littermates (db/+m). The results were compared with those after troglitazone administration under the same conditions. Despite hyperinsulinemia, hepatic glucose-6-phosphatase (G6Pase) and fructose-1,6-bisphosphatase (FBPase) activities are higher in db/db than in db/+m mice. Dietary administration of DHEA and that of troglitazone for 15 days to respective groups of five mice each significantly decreased blood glucose in db/db mice and hepatic G6Pase and FBPase activities in both db/db and db/+m mice. Hepatic G6Pase and FBPase activities showed a linear relationship with blood glucose in all groups of mice, suggesting that the activities of G6Pase and FBPase are closely related to blood glucose levels. Because androstenedione, a DHEA metabolite, barely affected either of these enzyme activities or blood glucose in db/db mice, the actions of DHEA, which are similar to those of troglitazone, are presumed to be caused by DHEA itself. DHEA is considered to be a modulating agent for the activities of hepatic gluconeogenic enzymes in db/db mice. (+info)
Oxythiamine and dehydroepiandrosterone induce a G1 phase cycle arrest in Ehrlich's tumor cells through inhibition of the pentose cycle.
(16/967)
Transketolase (TK) reactions play a crucial role in tumor cell nucleic acid ribose synthesis utilizing glucose carbons, yet, current cancer treatments do not target this central pathway. Experimentally, a dramatic decrease in tumor cell proliferation after the administration of the TK inhibitor oxythiamine (OT) was observed in several in vitro and in vivo tumor models. Here, we demonstrate that pentose cycle (PC) inhibitors, OT and dehydroepiandrosterone (DHEA), efficiently regulate the cell cycle and tumor proliferation processes. Increasing doses of OT or DHEA were administered by daily intraperitoneal injections to Ehrlich's ascites tumor hosting mice for 4 days. The tumor cell number and their cycle phase distribution profile were determined by DNA flow histograms. Tumors showed a dose dependent increase in their G0-G1 cell populations after both OT and DHEA treatment and a simultaneous decrease in cells advancing to the S and G2-M cell cycle phases. This effect of PC inhibitors was significant, OT was more effective than DHEA, both drugs acted synergistically in combination and no signs of direct cell or host toxicity were observed. Direct inhibition of PC reactions causes a G1 cell cycle arrest similar to that of 2-deoxyglucose treatment. However, no interference with cell energy production and cell toxicity is observed. PC inhibitors, specifically ones targeting TK, introduce a new target site for the development of future cancer therapies to inhibit glucose utilizing pathways selectively for nucleic acid production. (+info)