Search results for "Dihydrotestosterone"
showing 10 items of 16 documents
Sex hormones modulate pathogenic processes in experimental traumatic brain injury.
2018
Clinical and animal studies have revealed sex-specific differences in histopathological and neurological outcome after traumatic brain injury (TBI). The impact of perioperative administration of sex steroid inhibitors on TBI is still elusive. Here, we subjected male and female C57Bl/6N mice to the controlled cortical impact (CCI) model of TBI and applied pharmacological inhibitors of steroid hormone synthesis, that is, letrozole (LET, inhibiting estradiol synthesis by aromatase) and finasteride (FIN, inhibiting dihydrotestosterone synthesis by 5α-reductase), respectively, starting 72 h prior CCI, and continuing for a further 48 h after CCI. Initial gene expression analyses showed that andro…
Peripheral androgen blockade versus glandular androgen suppression in the treatment of hirsutism.
1991
Hirsutism in women is often explained on the basis of abnormal peripheral androgen metabolism. To determine whether serum markers of ovarian, adrenal, or peripheral androgen production may be helpful determinants in the treatment of hirsutism and to compare the efficacy of treatment with dexamethasone or spironolactone, 20 hyperandrogenic hirsute patients were treated for up to 2 years. Eleven women who were selected on the basis of sensitivity to dexamethasone were treated with a daily dose of 0.37 mg dexamethasone and had androgen levels suppressed into the normal range. Although significant (P less than .05), Ferriman-Gallwey scores decreased only by 20%: 14.2 +/- 0.5 to 11.4 +/- 0.6. Ni…
Androgen receptor activation by polychlorinated biphenyls
2013
The exposure to environmental endocrine disrupting compounds (EDC), as polychlorinated biphenyls (PCBs), widely diffused in the environment may produce epigenetic changes that affect the endocrine system. We found that PCBs activate AR transcriptional activity and that this effect is potentiated by the demethylase Jarid1b, a histone demethylase that catalyzes the removal of trimethylation of lysine 4 on histone H3 (H3K4me3), induced by PCB. The aim of the present study was to investigate the effect of the treatment of cultured cells (HEK293) with a mixture of the most diffused environmental PCBs and, also with dihydrotestosterone (DHT), on the functional interaction between AR and Jarid1b. …
Fluorinated and pegylated polyaspartamide derivatives to increase solubility and efficacy of Flutamide
2012
New fluorinated amphiphilic copolymers based on a biocompatible polyaspartamide have been prepared in order to obtain polymeric micelles useful for delivering anticancer drugs. In particular, α,β-poly(N-2-hydroxyethyl)-d,l-aspartamide (PHEA) has been derivatized with polyethylene glycol (PEG(2000)) and ethylendiamine (EDA). Both these portions form the hydrophilic part of the copolymer, while the hydrophobic moiety is given by 1,2,4-oxadiazoles: 5-pentafluorophenyl-3-perfluoroheptyl-1,2,4-oxadiazole (PPOX) or 3-carboxyethyl-5-pentadecafluoroheptyl-1,2,4-oxadiazole (CPOX). Copolymers named PHEA-PEG(2000)-EDA-PPOX and PHEA-PEG(2000)-EDA-CPOX have been prepared with various degrees of derivati…
Chemometric and chemoinformatic analyses of anabolic and androgenic activities of testosterone and dihydrotestosterone analogues
2008
Predictive quantitative structure-activity relationship (QSAR) models of anabolic and androgenic activities for the testosterone and dihydrotestosterone steroid analogues were obtained by means of multiple linear regression using quantum and physicochemical molecular descriptors (MD) as well as a genetic algorithm for the selection of the best subset of variables. Quantitative models found for describing the anabolic (androgenic) activity are significant from a statistical point of view: R2 of 0.84 (0.72 and 0.70). A leave-one-out cross-validation procedure revealed that the regression models had a fairly good predictability [q2 of 0.80 (0.60 and 0.59)]. In addition, other QSAR models were …
Alterations of peripheral testosterone metabolism after induced hypoprolactinemia in patients with prostatic carcinoma
1979
In 12 patients with advanced prostatic carcinoma the effect of bromocriptine-induced hypoprolactinemia on the peripheral androgen metabolism was investigated after 3H-testosterone injection under conditions that each individual served as his own control. After a 5-day significant prolactin suppression, the elimination of 3H-label 1 h after testosterone injection was about 45% and equal to pre-bromocriptine values. The recovery of dihydrotestosterone separated by silica gel T.L.C., however, was significantly augmented, resulting in a marked decrease of the testosterone/dihydrotestosterone ratio from 12.2 to 6.3. This induced 5alpha-reductase activity after prolactin suppression is in accorda…
Testosterone metabolism in benign prostatic hypertrophy: in vivo studies of gestonorone caproate and cyproterone acetate.
1976
Summary 18 patients with obstructive benign prostatic hypertrophy were studied. A 5-day treatment with gestonorone caproate (200 mg daily and 200 mg on alternate days) and cyproterone acetate (300 mg daily) suppressed the plasma LH and serum LH levels. Subsequently, H3-testosterone was injected intravenously and its elimination from plasma and uptake and metabolism in the BPH tissue studied. The elimination of total radioactivity and H3-testosterone from plasma was not altered after the 3 treatment regimens as compared to the control group. The uptake of total radioactivity into BPH tissue and its intraprostatic metabolism particularly to dihydrotestosterone was significantly suppressed in …
Steroid-growth factor interaction in human prostate cancer. 2. Effects of transforming growth factors on androgen metabolism of prostate cancer cells
1996
The ability of human prostate cancer cells to metabolize androgens was assessed through administration of physiological concentration (0.5-10 nM) of tritiated testosterone (T) as precursor and one-step analysis of both T degradation and products' formation by reverse-phase HPLC and on-line radioactive detection after either 24 h or 72 h incubation. Overall, different prostate cancer cells degraded T quite differently, favoring alternatively reductive or oxidative metabolic pathways. In particular, both LNCaP and DU145 cells retained high levels of unconverted T, with a limited production of androstenedione and its 17-keto derivatives and relatively high amounts of dihydrotestosterone (DHT) …
Androgen receptors and hormone sensitivity of a human prostatic cancer cell line (PC-3) are modulated by natural beta-interferon.
1994
Androgen receptors are expressed at a low level in the cell line PC-3, which does not respond to either androgens or antiandrogens. If these cells are exposed to natural beta-interferon (beta-IFN) a reduction in cell growth and an increase in androgen receptors, evaluated by both biochemical and immunocytochemical techniques, occur. This increase seems not to be related to a selective block of PC-3 in any phase of the cell cycle. Pretreatment with beta-IFN determines in PC-3 cells a partial responsiveness to the androgen dihydrotestosterone as reflected by the increase in cell number. Moreover, the antiandrogen hydroxyflutamide shows agonistic properties by increasing the cell number of PC-…
Effect of prolactin and the anti-prolactin bromocriptin on the testosterone uptake and metabolism in androgen-sensitive and insensitive canine organs
1976
Prolactin promotes the growth and function of the prostate in low doses, whereas high doses or previous castration reduce this effect. The antiprolactin bromocriptin should reverse the prolactin action. In the castrated dog the highest accumulation of H3-testosterone given i.v. occurred in the prostate as compared with muscle, urethra, penis, liver and kidney. Prolactin pretreatment increased the radiosteroid uptake only in the liver. Converseley, bromocriptin suppressed the tracer incorporation into the liver, but increased prostatic accumulation. The highest testerone reduction occurred in the prostate of the untreated castrated dogs as compared with other organs. Prolactin suppressed 5 a…