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At least 487 records · Page 27Linked to original sources
PubMed1975

Inhibition of the effects of alfathesin and other steroid anesthetics by catatoxic steroids in rats.

In rats, the sleeping time induced by overdosage with eight steroid anesthetics--alfathesin, 3-(3-oxo-17beta-hydroxy-19-nor-4-androsten-17alpha-yl)-propionic acid-lactone (SC-8109), 21-hydroxy=5alpha-pregnane-3,20-dione (P-234), 4-pregnene-3,11,20-trione (Bio.66), 17-hydroxy-3-oxo-4-androstene-17alpha-propionic acid-gamma-lactone(SC-5233),3alpha-hydroxy-5beta-pregnane-11,20-dione, 5beta-pregnane-3,11,20-trione (U-1373), and hydroxydione--was abolished or considerably reduced by a variety of catatoxic compounds, particularly 3beta-hydroxy-20-oxo-5-pregnene-16alpha-carbonitrile (PCN), 9alpha-fluoro-11beta,17-dihydroxy-3-oxo-4-androstene-17alpha-propionic acid potassium salt (CS-1), prednisolone, ethylestrenol and spironolactone. Phenobarbital and diphenylhydantoin, two non-steroidal stimulators of hepatic microsomal drug metabolism, were also highly effective. In contrast, triamcinolone, estradiol,progesterone, desoxycorticosterone and hydroxydione, which exert little or no catatoxic activity, failed to significantly diminish anesthesia or sedation.

Alfaxalone Alfadolone Mixture↗
PubMed1983

Steroid metabolism and steroid receptors in dimethylbenz(a)anthracene-induced rat mammary tumors.

Mammary tumors were induced in rats by treatment with dimethylbenz(a)anthracene. Cytosol receptors for 17 beta-estradiol and progesterone were estimated by means of sucrose density gradient centrifugation, and the metabolism of [14C]progesterone, [14C]testosterone, and 17 beta-[14C]estradiol by minced tumor tissue was studied. The estradiol receptor (ER) and progesterone receptor (PR) levels of the tumors varied considerably from less than 5 to 48 fmol/mg protein for ER and to 243 fmol/mg protein for PR. Considering a receptor level lower than 5 fmol/mg protein to be negative, four groups of tumors were found: ER-negative and PR-negative; ER-positive and PR-negative; ER-negative and PR-positive; ER-positive and PR-positive. In dimethylbenz(a)anthracene-induced tumor tissue, high 5 alpha-reductase and 20 alpha-hydroxysteroid dehydrogenase activities and somewhat lower 3 alpha-hydroxysteroid dehydrogenase and 6 alpha-hydroxylase activities were found. No aromatization was detectable. Steroids, especially estradiol, were also metabolized in a high degree to unextractable metabolites. It was concluded that steroid metabolism of dimethylbenz(a)anthracene-induced rat mammary tumors was not related to the ER and/or PR concentration of tumor tissue.

9,10-Dimethyl-1,2-benzanthracene↗
PubMed1978

Steroid spectrum in human urine as revealed by gas chromatography. II. Quantitative analysis of C19--C21O2-3 steroids.

The amounts of C19-C21O2-3 steroids excreted in the urine was determined in 35 individuals representing a normal healthy fraction of the adult population. The metabolites were determined after acid hydrolysis and simultaneous toluene extraction, in the form of acetyl derivatives, under isothermic conditions, on two columns. For the quantitative determination of the components and for ensuring reliability, two internal standards were applied. The preparatory steps, beginning with extraction from acidic media, were controlled by the addition to the urine of 4 beta, 5 beta-epoxycholestanone as a "marker" internal standard, while the "measurement" standard applied in gas chromatography was 5 alpha-cholestane. Quantitative measurements were carried out on a SE-30 column, androsterone and etiocholanolone were separated on a CHDMS column; the reliability of the determinations was checked by statistical analysis. The physiological values of some 8-9 of the most important steroid metabolites excreted in the urine, as averaged from the values measured for 23 women and 12 men, are discussed and compared with the data in the literature.

Adolescent↗
PubMed2002

Synthesis and biological evaluation of 4-(4-(alkyl- and phenylaminocarbonyl)benzoyl)benzoic acid derivatives as non-steroidal inhibitors of steroid 5 alpha-reductase isozymes 1 and 2.

The synthesis and biological evaluation of 4-(4-(alkyl- and phenylaminocarbonyl)benzoyl)benzoic acids (4a-4d) as non-steroidal inhibitors of steroid 5 alpha-reductase are described. The compounds were tested in vitro for inhibitory activity toward rat and human 5 alpha-reductase isozymes 1 and 2 at a concentration of 10 microM. The most active inhibitor for the human type 2 isozyme was 4-(4-(phenylaminocarbonyl)benzoyl)benzoic acid, compound 4c (IC50 = 0.82 microM).

5-alpha Reductase Inhibitors↗
PubMed2002

Synthesis and Biological Evaluation of 4-(4-(Alkyl-and Phenylaminocarbonyl)benzoyl)benzoic Acid Derivatives as Non-steroidal Inhibitors of Steroid 5alpha-Reductase Isozymes 1 and 2.

The synthesis and biological evaluation of 4-(4-(alkyl- and phenylaminocarbonyl)-benzoyl)benzoic acids (4a-4d) as non-steroidal inhibitors of steroid 5alpha-reductase are described. The compounds were tested in vitro for inhibitory activity toward rat and human 5alpha-reductase isozymes 1 and 2 at a concentration of 10 &mgr;M.The most active inhibitor for the human type 2 isozyme was 4-(4-(phenylaminocarbonyl)benzoyl) benzoic acid, compound 4c (IC (50) = 0.82 &mgr;M).

Journal Article↗
PubMed1983

Studies related to the metabolism of anabolic steroids in the horse: the metabolism of 1-dehydrotestosterone and the use of fast atom bombardment mass spectrometry in the identification of steroid conjugates.

The metabolism and urinary excretion of 1,2(n)-3H-1-dehydrotestosterone were studied in cross-bred gelded horses. Approximately 40% of the dose was excreted in 24 h. The steroid metabolites were extracted by Amberlite XAD-2 resin and fractionated into glucuronides and sulphoconjugates. Unchanged 1-dehydrotestosterone was the only component identified by gas chromatography mass spectrometry after solvolysis of the sulphoconjugates. Positive and negative ion fast atom bombardment mass spectra were obtained on the purified 1-dehydrotestosterone sulphoconjugate isolated from horse urine and on the alkali metal salts of three standard steroid conjugates. Spectra obtained in the different modes were of comparable intensity. Positive ion spectra were generally more complex due to the formation of alkali metal adduct ions containing several sodium cations. The most abundant ion in the negative ion spectra corresponded to the loss of the alkali metal cation to give [M]-. Thus, the structure of a conjugate can be defined from the combination of mass spectrometric techniques.

Anabolic Agents↗
PubMed1992

Oestrogen sulphatase activity in hormone-dependent and hormone-independent breast-cancer cells: modulation by steroidal and non-steroidal therapeutic agents.

Oestrogen sulphatase may play an important role in providing intracellular oestrogens from E1S for the growth and maintenance of breast tumours. In this study, we characterized oestrogen sulphatase in the hormone-dependent (ER/PR+) MCF-7 and in the hormone-independent (ER/PR-) MDA-MB-231 breast-cancer cells and, furthermore, examined its modulation by MPA, 4-OH-A4, tamoxifen, danazol, ethinyloestradiol and DHAS in both these cell types. Our detailed study of oestrogen sulphatase activity as a function of incubation time, E1S concentration and numbers of MCF-7 and MDA-MB-231 cells showed that more E1S was hydrolysed by MDA-MB-231 cells than by MCF-7 cells at all time points and all substrate concentrations. Additionally, although the Km values of E1S for oestrogen sulphatase in both MCF-7 and MDA-MB-231 cells were similar, the Vmax values, and therefore the activity, differed greatly. The effect of various steroidal and non-steroidal compounds also suggested differences in these 2 cell lines with respect to oestrogen sulphatase inhibition or stimulation. MPA significantly increased the hydrolysis of [3H]E1S in both cell lines, possibly through its effect on membrane fluidity. Tamoxifen increased E1S hydrolysis in MDA-MB-231 cells but not in MCF-7 cells, whereas 4-OH-A4 inhibited E1S in MCF-7 cells but not in MDA-MB-231 cells. Danazol (an isoxazol derivative of 17 alpha-ethinyltestosterone), 17 alpha-ethinyloestradiol and DHAS all significantly inhibited oestrogen sulphatase activity in both cell lines. Furthermore, danazol had a growth-inhibitory effect on both MCF-7 and MDA-MB-231 cells, although MCF-7 cells appeared to be more sensitive to growth inhibition by danazol.

Breast Neoplasms↗
PubMed1987

Inhibition of mouse oocyte cyclic AMP phosphodiesterase by steroid hormones: a possible mechanism for steroid hormone inhibition of oocyte maturation.

Testosterone, progesterone, and estradiol-17 beta each inhibit cAMP phosphodiesterase activity of mouse oocyte extracts in a concentration-dependent manner. This finding provides an explanation for the inhibitory effect of steroid hormones on germinal vesicle breakdown (GVBD) of mouse oocytes in vitro. Furthermore, it raises the possibility that steroid hormones present in follicular fluid participate in maintaining meiotic arrest in vivo by acting in a nonclassical manner.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1980

[Steroid transforming enzymes in microorganisms. XIII. Relationship between steroid structure and induction of 4-ene-3-oxosteroid: (acceptor)-1-ene-oxidoreductase in Nocardia opaca].

The induction of the 4-ene-3-oxosteroid: (acceptor)-1-ene-oxidoreductase in Nocardia opaca has been shown to be dependent on both hydrophilic and hydrophobic structural features of the steroid molecule, i.g. the nature of the oxygen function in positions 11 and 20 and the presence of the methyl group in position 10 influence the induction of the enzyme drastically. In this connection the metabolism of the steroid inductors being degradated during the induction process has been considered.

Enzyme Induction↗
PubMed1990

Effect of the steroidal androgen receptor antagonist Win 49,596 on steroid-induced benign prostatic hyperplasia in the castrate beagle dog.

The effects of the steroidal androgen receptor antagonist Win 49,596 on steroid-induced prostatic growth, histomorphology, and secretory function were studied in the castrate male beagle dog. At oral doses ranging from 0.625 to 40 mg/kg/day for 12 weeks, Win 49,596 inhibited prostatic growth in terms of both weight and total DNA in a dose-dependent manner. In addition, both the incidence and severity of diffuse glandular hyperplasia/hypertrophy were dose-dependently inhibited by Win 49,596, resulting in diffuse glandular atrophy. Prostatic secretory function was also inhibited by Win 49,596 treatment. The effects of Win 49,596 at a dosage of 40 mg/kg/day were similar to that observed for the nonsteroidal androgen receptor antagonist flutamide at 10 mg/kg/day. Oral administration of Win 49,596 to castrate dogs at a dosage of 40 mg/kg/day for 12 weeks failed to produce any evidence of agonist activity. These results demonstrate that Win 49,596 prevented the experimental induction of benign prostatic hyperplasia in dogs and suggest that on further evaluation this compound may be efficacious in the treatment of the human disease.

Androgen Antagonists↗
PubMed1989

Translational energy release and stereochemistry of steroids. 14. Epimeric dihydroxy steroids of the androstane series.

The stereochemistry of dihydroxy steroids, both the mode of the A/B ring junctions and the configuration of OH groups, may be determined from translational energy (T50%) measurements for the loss of a CH.3 radical, from the ratios of metastable-ion peak heights to those of the main beam (determined for the dehydration reactions), and by comparing unimolecular and collision-induced, mass-analysed ion kinetic energy spectra of the new main beam of [M-H2O]+ ions (i.e. those formed via dehydration of metastable molecular ions of epimeric hydroxy steroids in the first field-free region of a double-focusing mass spectrometer.

Androstanes↗
PubMed1975

Morphology of the epididymis of the cock (Gallus domesticus) and its effect upon the steroid sex hormone synthesis. II. Steroid sex hormone synthesis in the tubuli epididymidis and the transformation of the ductuli aberrantes into hormone producing noduli epididymidis in the capsule of the adrenal gland of the capon.

Distinct histochemical and ultrastructural signs of a steroid hormone synthesis are found in the sexually mature cock, particularly in the ductuli efferentes proximales of the main part of the epididymis and in the blind ends of the ductuli aberrantes of the appendix epididymidis. These signs are more distinct in the appendix epididymidis of the capon since the blind ends of the ductuli aberrantes transform into steroid sex hormone producing noduli epididymidis after they sprout out intensively and branch inside or beneath the adrenal capsule. The signs of virility were lost immediately after castration. They become more distinct again due to the hormonal activity of the noduli. Due to the morphologic agreement the noduli epididymidis of the capon are homologous to the noduli epoophori of the hen.

Androgens↗
PubMed1977

Results of reflex photometric determinations of vasoconstriction after topical steroid application. Tachyphylaxis, relative and absolute refractory phase after single and multiple application of steroid.

After a repeated intensive topical application (4-h rhythm), there it is phase already after 28 h in which the cutaneous vessels are insensitive (refractory) to constrictor stimuli due to steroids. This refractory phase lasts for at least 68 h. A single local application of steroid likewise leads to a diminished vasoreactivity for a limited time. The relative refractory phase is limited to 96 h under the given experimental conditions.

Administration, Topical↗
PubMed1988

Inhibition of granulocyte function by steroids is not limited to corticoids. Studies with sex steroids.

Noting that corticosteroid doses required for protection in shock models exceeded those required to saturate glucocorticoid receptors in mammalian cells, we postulated a nonspecific physicochemical effect of steroids upon the cell membrane, and therefore tested three noncorticoid steroids for their effects on granulocyte function. All three (conjugated equine estrogen, a synthetic progestogen, and a synthetic androgen) behaved in manner analogous to corticoids at similar concentrations, inhibiting granulocyte aggregation, chemotaxis, and chemiluminescence, as well as binding to the granulocytes of the synthetic oligopeptide agonist f-Met-Leu-Phe. Estrogen was further shown to reduce granulocyte membrane fluidity, assessed by electron paramagnetic resonance. We propose that the unique effects of extremely high-dose corticosteroids are not mediated via the glucocorticoid receptor, but result rather from physicochemical effects of the drugs upon the membranes of effector cells.

Adrenal Cortex Hormones↗
PubMed1989

Follicular fluid steroid content and in vitro steroid secretion by granulosa-lutein cells from individual follicles among different stimulation protocols for in vitro fertilization-embryo transfer.

The in vitro steroidogenic capacity of granulosa-lutein (G-L) cells aspirated from individual follicles during cycles of in vitro fertilization-embryo transfer was examined and compared among three different stimulation protocols: human menopausal gonadotropins (hMG), clomiphene citrate (CC) and hMG, and follicle stimulating hormone (FSH). In addition, the clinical outcome of the patients in each protocol was examined. After 3 days of culture in basal medium, fresh medium with or without androstenedione (A) (10(-7) M) was added for 24 hr, at which time medium was obtained for measurement of progesterone (P) and estradiol (E) content. Follicular fluid (FF) P, E, and A were measured in each follicle and compared among protocols. FF from individual follicles in patients stimulated with FSH contained higher levels of P compared to FF from patients stimulated with hMG or CC/hMG, while E was higher in patients stimulated with CC/hMG compared to FSH or hMG. FF levels of A were not significantly different among the protocols. In vitro steroid secretion revealed a progressive increase in P secretion in contrast to decreasing E secretion when one compares CC/hMG, hMG, and FSH. Patients undergoing ovarian hyperstimulation with FSH had significantly more atretic oocytes identified at the time of oocyte harvest compared to patients undergoing ovarian hyperstimulation with CC/hMG or hMG. The hMG protocol yielded significantly fewer fertilized oocytes, cleaved embryos, and transferred embryos, compared to the CC/hMG and FSH protocol, however, there was no significant difference in pregnancy rate among the three protocols. These data demonstrate that individual follicles contain G-L cells with markedly different abilities to luteinize in vitro as assessed by steroid secretion.(ABSTRACT TRUNCATED AT 250 WORDS)

Androstenedione↗
PubMed1988

Steroids do not alter pancreatic blood supply in hypovolemic dogs: implications on steroid action in acute pancreatitis.

A recent report from our laboratory showed that pancreatic inflammation induced by hypovolemic shock can be explained to some extent by spoliation in pancreatic perfusion as revealed by electromagnetic flow determinations on the gastroduodenal artery (GDA). On the other hand, when given early in the course of hypovolemic shock, methylprednisolone sodium succinate (MPSS) alleviated pancreatic inflammation as evidenced by gross and histological findings. Five dogs (18-23 kg) were submitted to a 3-hour hypovolemic shock (mean arterial blood pressure, MABP = 50 mm Hg) and received during bleeding 35 mg/kg of MPSS over a 30 min period. Recordings of cardiac output (CO), MABP, regional blood flows in the GDA and superior mesenteric (SMA) arteries were taken every 15 min. The effect of MPSS was appreciated by comparing GDA flow variations in this group with those previously published of a control group comprised of 12 dogs submitted to 3 hours of hypovolemic shock without steroids; operative protocol was in all points similar in both groups. At no time were any significant changes noted when MPSS was added as far as CO and GDA flows were concerned. In other words, the beneficial action of steroids on hypovolemic pancreases cannot be explained by alteration in regional blood flow.

Acute Disease↗
PubMed2006

Steroid sparing effect of a herbal preparation in steroid-dependent nephrotic syndrome.

Investigations on plants are revealing the potential therapeutic benefits of medicinal herbs in treating immunological disorders. Nephrotic syndrome has emerged as an immunological disorder. Steroid dependence poses a therapeutic challenge in the management of nephrotic syndrome. Our pilot study compares the efficacy of an ayurvedic polyherbal preparation 'Shathavaryadi Yoga (NS001)' with oral cyclophosphamide in maintaining remission in steroid-dependent nephrotic syndrome.

Adult↗