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At least 505 records · Page 28Linked to original sources
PubMed1995

Anabolic-androgenic steroid and adrenal steroid effects on hippocampal plasticity.

Anabolic-androgenic steroids (AAS) are synthetic androgen-like compounds which are taken in high doses by athletes with the intention of enhancing muscular appearance, strength and/or athletic performance. Recent research indicates that high doses of AAS may influence the functions of the hippocampus. This evidence led us to explore the extent to which chronic AAS treatments influence spatial memory and the integrity of the hippocampus in the rat. Gonadally intact adult male Long-Evans rats were treated with either the AAS methandrostenolone, a steroid 'cocktail' (TNB; testosterone cypionate, boldenone undecylenate and nandrolone decanoate), or the oil vehicle daily for 12 weeks. A group of male rats treated with corticosterone (CORT; 10 mg/day) was also examined. Spatial memory was assessed in the Morris water maze after 10 weeks of hormone treatment. At 12 weeks, the animals were sacrificed, blood collected and the brain sectioned to assess hippocampal cell number. There were no impairments in the acquisition or retention of the Morris water maze in any hormone treatment group. Although serum testosterone levels were elevated in rats treated with TNB relative to the oil controls, neither the TNB or methandrostenolone treatments produced changes in hippocampal cell number. Serum CORT levels were significantly elevated in the rats treated with CORT and cell loss (15%) was detectable in the CA3b subfield in this group of animals. These results indicate that the AAS administered in the present study were not detrimental to hippocampal spatial memory or cell survival and that, while chronic CORT may produce mild hippocampal cell loss, this loss is not accompanied by deficits on a spatial memory task.

Animals↗
PubMed1985

Possible steroid binding site common to adrenal cytochrome P-450scc and prostatic steroid binding protein.

By searching the entire PIR-protein-sequence data base, we have found that a dodecapeptide sequence in bovine adrenal cytochrome P-450scc is closely related to that in rat prostatic steroid binding protein. The two proteins belong to unrelated protein families, but both have steroids as substrates or ligands. Thus, the dodecapeptides may be important for substrate/ligand recognition in the individual proteins.

Adrenal Glands↗
PubMed1989

Microbial transformations of steroids--IV. 6,7-Dehydrogenation; a new class of fungal steroid transformation product.

Microbial steroid dehydrogenation is quite common. The reaction seems to occur mainly in bacteria and usually results in hydrogen abstraction from positions C(1)-C(2) and/or C(4)-C(5) with occasional aromatisation of ring A. We have screened large numbers of fungal cultures for their ability to monohydroxylate steroids at unusual sites and in the course of our investigations we have identified seven fungal strains capable of dehydrogenating ring B of progesterone and androstenedione at positions C(6)-C(7). Microbiological dehydrogenation at this site seems not to have been reported previously. The structures of the metabolites isolated from progesterone, and the producing fungi, are: 6-dehydroprogesterone (Botryodiplodia theobromae), 11 alpha-hydroxy-6-dehydroprogesterone (Botryosphaerica obtusa, Mucor racemosus and Nigrospora sphaerica), 12 alpha-, 15 beta- and 16 alpha-hydroxy-6-dehydroprogesterones (B. obtusa) and 14 alpha-hydroxy-6-dehydroprogesterone (Apiocrea chrysosperma) [1]. From androstenedione we isolated 6-dehydroandrostenedione (Absidia coerulea and Curvularia lunata) and 6-dehydrotestosterone (C. lunata).

Androstenedione↗
PubMed1986

Relative binding of certain steroids of low polarity to human sex hormone-binding globulin: strong binding of 2-methoxyestrone, a steroid lacking the 17 beta-OH group.

The cross-reactivities for binding sites on human sex hormone-binding globulin (SHBG) of a number of steroids of low polarity, including progesterone and estrogen metabolites, were studied. Binding relative to testosterone (100%) was low (less than or equal to 3%) except for 2-methoxyestrone (81%), 3-acetoxyestradiol (16%), 4-methoxyestradiol (6%), 3 beta-hydroxy-5 beta-pregnan-3-one (5.8%), 5 alpha-dihydrodeoxycorticosterone (4.5%), deoxycorticosterone (4%), 20 alpha-hydroxy-5 alpha-pregnan -3-one (4%), 4-methoxyestrone (4%) and 5 alpha-dihydroprogesterone (3.5%). 2-Methoxyestrone is the only steroid lacking a 17 beta-hydroxyl group which binds to SHBG with strong affinity.

Binding, Competitive↗
PubMed1977

Effect of high concentrations of non-steroidal and steroidal antiinflammatory drugs on prostaglandin-induced contractions of the guinea-pig isolated ileum.

In addition to their well-known effect at low concentrations on prostaglandin synthesis or their release and production, 11 non-steroidal antiinflammatory drugs and 4 antiinflammatory steroids exhibit at high concentrations a direct antagonism on certain prostaglandin actions. This is demonstrated on PGE1- and PGF2alpha-induced contractions of guinea-pig isolated ileum when compared to acetylcholine-induced contractions. This inhibitory effect is totally reversible after washing out the drugs from the organ bath.

Animals↗
PubMed1991

Effects of steroidal and non-steroidal antiandrogens on the androgen binding properties of the rat ventral prostate androgen receptor.

Steroidal (cyproterone acetate) and non-steroidal (RU23908 and hydroxyflutamide) antiandrogens are able to block testosterone-induced increases in nuclear androgen receptor (AR) in the prostate of 1-day orchidectomized rats, but when given alone, RU23908 and hydroxyflutamide increase nuclear AR (RU23908 greater than hydroxyflutamide) in the same animal model. The increases in nuclear AR induced by antiandrogen alone or with testosterone alone are blocked by cycloheximide 1 h after administration, suggesting that androgen or antiandrogens induce de novo AR synthesis. Concomitant to nuclear AR accumulation, testosterone is able to induce depletion of cytosol and microsomal AR. Blockade of testosterone-induced depletion of microsomal AR, but not of cytosol AR, occurs in the presence of antiandrogens. Cyproterone acetate has a higher relative binding affinity (RBA) for microsomal AR and cytosol AR than RU23908 or hydroxyflutamide. This phenomenon is in good agreement with the degree of inhibition by these compounds of the association rate of androgen for the microsomal AR. This correlation between RBA and inhibition of the initial rate of hormone binding to the receptor is not found for cytosol AR. The results show that antiandrogens are not 'pure' antagonists of androgen action and they are potent agonists in the absence of testosterone. Furthermore, testosterone alone or antiandrogens per se regulate AR levels acutely by protein-synthesis dependent mechanisms of action, in rat ventral prostate.

Androgen Antagonists↗
PubMed1991

In vivo and in vitro studies on sex steroid binding protein (SBP) regulation in rainbow trout (Oncorhynchus mykiss): influence of sex steroid hormones and of factors linked to growth and metabolism.

The respective roles of sex steroids and hormones related to growth and metabolism, on SBP regulation have been studied in rainbow trout. In vivo, oestradiol (E2) supplementation induces a slow but significant increase of plasma SBP concentration. Testosterone or cortisol injections have no effect. In vitro, the steroid binding protein that accumulates in incubation medium of hepatic cell primary cultures has been characterized and found to be similar to blood SBP. Its production is increased by addition of E2 (maximum: +300%). This effect develops slowly over several days of culture and is dose dependent; as little as 1-10 nM E2 is effective. Recombinant rainbow trout GH (rtGH)--0.01 to 1 microgram/ml--also increases SBP accumulation as compared to control cells and seems to maintain SBP production over culture duration. In preliminary experiments, (1) insulin-like growth factor (IGF) and SBP concentrations were found to change inversely after a 4 days stimulation with increasing concentrations of GH; (2) recombinant human IGF1 (250 ng/ml) tended to be inhibitory when SBP production was expressed per mg of total cellular protein, and a micromolar concentration of bovine insulin was clearly inhibitory. Other hormones tested in vitro: triiodothyronine (10-1000 nM), thyroxine (100 nM), 17 alpha, 20 beta-dihydroprogesterone (10-2000 nM), and testosterone (1-1000 nM) did not influence SBP concentration in hepatic cells culture media.

Animals↗
PubMed1996

Direct interactions of androgenic/anabolic steroids with the peripheral benzodiazepine receptor in rat brain: implications for the psychological and physiological manifestations of androgenic/anabolic steroid abuse.

The peripheral benzodiazepine receptor (PBR) is a mitochondrial protein involved in regulating steroid synthesis and transport. We report here the effects of androgenic/anabolic steroids (AAS) on the binding of the PBR-specific ligand [3H] PK11195 to male rat brain cortical synaptoneurosomes. Two synthetic AAS, stanozolol and 17beta-testosterone cypionate (17beta-cyp), significantly inhibited 1 nM [3H] PK11195 binding at concentrations greater than 5 and 25 microM, respectively. Stanozolol was the most effective inhibitor, reducing [3H] PK11195 binding by up to 75%, compared to only 40% inhibition by 17beta-cyp, at 50 microM AAS concentration. Two other AAS, 17alpha-methyltestosterone and nortestosterone decanoate, were incapable of inhibiting [3H] PK11195 binding at concentrations up to 50 microM. On the basis of Scatchard/Rosenthal analysis, [3H] PK11195 binds to two classes of binding sites, and the inhibition of [3H] PK11195 binding by stanozolol appears to be allosteric, primarily reducing binding to the higher affinity [3H] PK11195 binding site. These results, in combination with earlier studies indicating the direct effects of AAS on the function of additional central nervous system receptor complexes, suggest that the behavioral and psychological effects of AAS result from the interactions of AAS with multiple regulatory systems in the brain.

Anabolic Agents↗
PubMed2003

6-(2-adamantan-2-ylidene-hydroxybenzoxazole)-O-sulfamate: a potent non-steroidal irreversible inhibitor of human steroid sulfatase.

We report the synthesis and results from the in vitro evaluation of 6-(adamantan-2-ylidene-hydroxybenzoxazole)-O-sulfamate 1 as an irreversible inhibitor of human steroid sulfatase (STS). Highly straightforward, condensation of 2-methyl-6-hydroxybenzoxazole with 2-adamantanone, subsequent elimination of water and sulfamoylation provide the title compound in 45% overall yield from the inexpensive 2,4-dihydroxyacetophenone. 1 was found to be a potent irreversible inhibitor of purified human steroid sulfatase (STS) and specific for this enzyme relative to human arylsulfatases A and B. In cellular assays with human keratinocytes, sebocytes and fibroblasts, 1 blocked STS activity with IC(50) values in the range of 0.15-0.8 nM, and in MCF-7 breast cancer cells with IC(50)=2.3 nM, while it did not bind to estrogen receptors alpha and beta. Thus, 1 is a candidate for further investigation of its potential as a drug to be used in androgen- and estrogen-dependent diseases.

Enzyme Inhibitors↗
PubMed1987

Plasma levels of C-19 steroids and 5 alpha-reduced steroid glucuronides in hyperandrogenic and idiopathic hirsute women.

In the present study, the authors measured the plasma levels of unconjugated and glucuronide (G) derivatives of C-19 steroids in hirsute women divided into two groups, depending upon their dehydroepiandrosterone sulfate (DHEAS). This quite restrictive classification was the result of an arbitrary decision of the authors, who wanted to focus interpretation of their data on DHEAS, the well-known adrenal androgen. In the hyperandrogenic hirsute woman (HH), the DHEAS levels were higher than 3.0 micrograms/ml; in idiopathic hirsute women (IH), values of DHEAS were comparable to those observed in normal women (1.2 to 2.5 micrograms/ml). In the HH group, the levels of dehydroepiandrosterone, androstenedione, androst-5-ene-3 beta,17 beta-diol (delta 5-diol), testosterone, dihydrotestosterone (DHT), androstane-3 alpha, 17 beta-diol (3 alpha-diol), androstane-3 beta,17 beta-diol (3 beta-diol), androsterone (ADT), DHTG, 3 alpha-diol-G, 3 beta-diol-G, and ADTG were higher than the normal range whereas, in the IH group, only delta 5-diol, DHT, 3 beta-diol-G and ADTG were elevated. These data are compatible with the hypothesis that the plasma levels of steroid G represent the peripheral formation of androgen in target tissues. Because the pattern of androgen metabolism is most probably changed in many cases of hirsutism, these data suggest that for research purposes, it would be preferable to measure 3 beta-diol-G and ADTG in addition to 3 alpha-diol-G in order to gain additional information concerning androgen metabolites in this disorder.

Adolescent↗
PubMed1996

The effects of anabolic androgenic steroids on serum ubiquinone and dolichol levels among steroid abusers.

We measured serum ubiquinone and dolichol concentrations in 13 men while they abused anabolic androgenic steroids (AAS) and during the following withdrawal period. Serum total, high-density lipoprotein (HDL), and low-density lipoprotein (LDL) cholesterol and triglycerides were also determined. AAS administration increased serum ubiquinone by 68% (P < .001) and decreased serum dolichol by 30% (P < .002). Both nonsterol isoprenoid levels in plasma correlated with the AAS dose, ubiquinone positively (P < .001) and dolichol negatively (P < .002). When the subjects were taking steroids, the ubiquinone to LDL ratio was 42% higher than during the withdrawal period. In conclusion, our study suggests that AAS have an influence on the by-products of the mevalonate pathway.

Adult↗
PubMed1991

Long-term cyclosporine A treatment of steroid-resistant and steroid-dependent nephrotic syndrome.

Eighteen patients with steroid-resistant nephrotic syndrome (SRNS) and steroid-dependent nephrotic syndrome (SDNS) were treated with cyclosporine A (CyA) (6 mg/kg/d) for 2 to 29 months. CyA levels were monitored monthly and plasma levels by Abbott TDX (Therapeutic Drug Analyzer System) fluorescence polarization immunoassay were maintained at 100 to 150 ng/mL. The corticosteroid dosage administered at the time CyA therapy was initiated was variable and was continued following CyA therapy. Six of these patients (all with SDNS and minimal change nephrotic syndrome [MCNS]) had been treated with one or more courses of cytotoxic drug therapy, and all had clinical evidence of corticosteroid toxicity after receiving corticosteroid therapy for 26 to 120 months. The corticosteroid dosage was reduced by slow tapering and was ultimately discontinued in six patients. These patients were maintained on CyA monotherapy for 7 to 21 months at a dose of 3.2 to 6.7 mg/kg/d. Following 11 to 29 months of CyA therapy, seven patients underwent an elective renal biopsy, which showed nephrotoxicity in all seven. This led to discontinuation of CyA in four patients. Following discontinuation of CyA monotherapy, all four patients relapsed within 2 to 4 months. CyA therapy did not achieve a remission in 10 patients with SRNS regardless of the presence of focal segmental glomerulosclerosis (FSGS) or MCNS on renal biopsy. In conclusion, CyA has limited effectiveness in patients with SDNS who manifest corticosteroid toxicity; however, CyA should be used cautiously because of the potential for CyA nephrotoxicity and the failure to obtain a sustained remission following discontinuation of CyA monotherapy. CyA dependence is substituted for corticosteroid dependence.

Biopsy↗
PubMed1999

Steroids and steroid-like compounds.

Athletes have been searching for an "edge" in competition as long as there has been a reward for success. Anabolic-androgenic steroids have been the most popular of these ergogenic aids when winning is the only goal. The authors present a concise review of these substances, their prevalence, efficacy, adverse effects, and legality. This article also presents a steroid user profile and discusses physician perception and management of a patient who uses these drugs. The popular precursors of testosterone, dehydroepiandrosterone, and androstenedione are discussed with a review of the limited available data on these substances.

Adolescent↗
PubMed1999

The influence of exogenous steroid hormones on steroid receptors, uterine histological structure and the bacterial flora of the normal bitch.

Oestrogen (ER) and progesterone (PR) receptors have been shown to vary in both concentration and distribution during the oestrous cycle of the bitch, influenced by the normal changes in endogenous reproductive hormones. The influence of exogenous steroid hormones on steroid receptors and the histological structure of the uterus was studied in two groups of parous Beagle bitches. Group A (n = 6) were treated with progesterone (P4) in oil i.m. (3 mg/kg) in late metoestrus on the day that peripheral plasma P4 concentrations were first identified as <10 ng/ml, and subsequently once weekly on three other occasions. Group B (n = 6) were treated with a single i.m. injection of MPA (50 mg, 4.2-5.6 mg/kg) following the same protocol. Full-thickness uterine wall biopsies were obtained from the mid part of one horn 2-7 days after the last (fourth) injection of P4 or MPA. During the subsequent oestrus, when peripheral plasma P4 concentrations were between 8 and 10 ng/ml, each bitch in both groups (n = 12) received a single injection of oestradiol benzoate (ODB) in oil i.m. (7.5 mg, 0.63-0.84 mg/kg). All bitches had an ovariohysterectomy 7 days later. Full-thickness uterine wall samples were obtained from the mid part of the intact horn and other parts of the uterus. Swabs were taken from the uterine lumen for bacteriological examination; all were sterile. Tissue samples were sectioned and examined for evidence of lesions, and stained for ER and PR receptors using an immunocytochemical method. The immunoreactivity was scored semiquantitatively, incorporating both the intensity and distribution of specific staining of the receptors using a simplified histoscore (H-score). At the time of ovariohysterectomy, fluid had accumulated in the isolated section of the uterine horn distal to the point of biopsy; the volume was greater in the MPA-treated bitches. There was also evidence in some sections of histological changes in the endometrium. Variations in the expression of both ER and PR were seen between bitches, which may have been due to some not being in mid-metoestrus at the time of treatment. In general, ER scores were low after P4 and MPA treatment, but following ODB there was a significant (P<0.05) increase in ER expression in all parts of the endometrium. PR scores were zero in the glandular epithelium of all 12 bitches after P4, MPA and ODB treatment, whereas in the other parts of the endometrium they were generally moderate to high. Following treatment with ODB, PR generally increased in the three regions of the endometrium where PR were present. The study shows that ER and PR distribution and expression in the endometrium of bitches can be modified by P4, MPA and ODB, with evidence of individual variation.

Animals↗
PubMed1997

Effects of low steroid doses administered in the mid and late follicular phase on the LH surge, ovarian steroids and follicular maturation in eumenorrheic women.

The effects of four low doses of synthetic steroids, administered orally and starting on day 8 (group I) or on day 10 of the menstrual cycle (group II), upon LH surge, ovarian steroidogenesis, follicular maturation and menstrual cycles were studied in 10 eumenorrheic women. The results revealed that the day before the LH surge, the highest level of estrone-3-glucuronide was observed in both groups. Twenty-four hours after the last dose, the maximum urinary LH levels were recorded in groups I (day 11), and II (day 13). Pregnanediol-3 alpha glucuronide remained low during the study in group I, whereas in group II a gradual rise of this hormone starting on day 13 was registered and the highest level was found at day 21 of the menstrual cycle. Follicular maturation and ovulation were observed only in women from group II. Short and normal length cycles were recorded in groups I and II, respectively. In summary, low doses of exogenous synthetic steroids administered on day 8, but not on day 10 of the cycle, inhibit follicular maturation and ovulation.

Adult↗
PubMed2001

Formestane, a steroidal aromatase inhibitor after failure of non-steroidal aromatase inhibitors (anastrozole and letrozole): is a clinical benefit still achievable?

BACKGROUND: There are few clinical data on the sequential use of aromatase inhibitors (AI). This paper focuses on the relevance of clinical benefit CB (CR + PR + SD > or = 6 months) in postmenopausal metastatic breast cancer (MBC) patients treated with the steroidal aromatase inhibitor (SAI) formestane (FOR). who had already received non-steroidal aromatase inhibitor (nSAI): letrozole (LTZ) or anastrozole (ANZ). PATIENTS AND METHODS: Twenty postmenopausal women with MBC were analysed in this retrospective two-centre study with the sequence nSAI-FOR. When receiving ANZ, 1 of 11 achieved a complete response and 9 of 11 a stable disease > or = 6 months, and receiving LTZ 1 of 9 achieved a partial response and 4 of 9 a stable disease > or = 6 months. The analysis of the entire population treated with FOR showed an overall CB of 55% (11 of 20) with a median duration of 15 months and median time to progression (TTP) of 6 months. CONCLUSIONS: Formestane 250 mg once bi-weekly seems to be an attractive alternative third-line hormonal therapy for the treatment of patients with MBC, previously treated with nSAI.

Adult↗
PubMed2003

A novel steroid receptor co-activator protein (SRAP) as an alternative form of steroid receptor RNA-activator gene: expression in prostate cancer cells and enhancement of androgen receptor activity.

We have cloned a cDNA coding for a novel steroid receptor co-activator protein termed SRAP from a rat prostate library. Although the nucleotide sequence of the SRAP has 78.2% identity to that of the human steroid receptor RNA activator (SRA), a novel RNA molecule which was reported to act as an RNA transcript without being translated into protein [Lanz, McKenna, Onate, Albrecht, Wong, Tsai, Tsai and O'Malley (1999) Cell 97, 17-27], the cDNA of SRAP is capable of generating a functional protein. Glutathione S-transferase pull-down assays showed that SRAP associates with the partial androgen receptor (AR) protein composed of a DNA-binding domain and an activation function 2. Luciferase assays demonstrated that SRAP enhances the transactivation activity of the AR, the glucocorticoid receptor and the peroxisome proliferator-activated receptor gamma(1) in a ligand-dependent manner. Using a green fluorescent protein (GFP) fusion-protein construct, we demonstrated in vivo translation of the GFP-SRAP fusion protein in HeLa cells co-transfected with pSG5AR and reporter gene in the presence of 5 alpha-dihydrotestosterone (DHT). Co-transfection of the GFP-SRAP fusion protein expression plasmid enhanced the transactivation activity of AR whereas incorporation of mutations in SRAP of the fusion protein resulted in loss of enhancement of the transactivation activity. Northern blot analysis and reverse transcriptase PCR assays showed that SRAP and SRA are expressed in rat and human prostate cancer cell lines respectively. In HeLa cells and the human prostate cancer cells line DU-145, co-transfected with SRAP, the DHT-dependent transactivation activities of AR were not completely inhibited by the anti-androgen flutamide, but the transactivation activities still remained high even in the presence of 5 microM flutamide, suggesting that SRAP may play an important role in enhancing AR activity in prostate cancer.

Amino Acid Sequence↗
PubMed2005

Oral mizoribine pulse therapy for patients with steroid-resistant and frequently relapsing steroid-dependent nephrotic syndrome.

BACKGROUND: We investigated the efficacy of oral mizoribine pulse therapy (mizoribine-pulse) for cyclosporin (CyA)-dependent, steroid-resistant nephrotic syndrome (SRNS) and frequently relapsing, steroid-dependent nephrotic syndrome (FR-SDNS). METHODS: One child with CyA-dependent SRNS and eight children with CyA-dependent FR-SDNS were treated with mizoribine-pulse (daily dose: 10 mg/kg; maximum total dose 500 mg). We compared clinical manifestations before and after mizoribine-pulse, and studied the changes in serum mizoribine concentration in each patient on days when mizoribine was administered. RESULTS: Four patients had no subsequent relapses (responders). Two of the four responders discontinued prednisolone and CyA, the other two discontinued CyA. Although each of the five other patients (non-responders) experienced single subsequent relapses, the dosages of prednisolone and CyA after mizoribine-pulse were decreased significantly compared with before mizoribine-pulse. The peak blood concentration of mizoribine in the responders was higher than in the non-responders (3.6+/-0.9 vs 1.8+/-0.4 microg/ml). CONCLUSIONS: Mizoribine-pulse may be effective for some patients with CyA-dependent SRNS and FR-SDNS.

Administration, Oral↗