Effect Of Various Steroids Research Articles

Letter: Effect of various steroids and ACTH on methyprylon plasma levels and sleeping time in rats.

Letter: Effect of various steroids and ACTH on methyprylon plasma levels and sleeping time in rats.

Effects of various steroids on platelet-derived endothelial cell growth factor (PD-ECGF) and its mRNA expression in uterine endometrial cancer cells

Progestins diminish the estrogen-induced angiogenic potential related to basic fibroblast growth factor (FGF) and vascular endothelial growth factor (VEGF) in uterine endometrial cancer cells. This led us to study the effect of various steroids on the expression of platelet-derived endothelial cell growth factor (PD-ECGF) as the other pertinent angiogenic factor in well-differentiated uterine endometrial cancer cell line Ishikawa. In Ishikawa cells, estradiol induced the expression of PD-ECGF and its mRNA. The estrogen-induced expression was increased approximately two-fold by progesterone and by its metabolite, 17α-hydroxyprogesterone, but not by medroxyprogesterone acetate (MPA). Therefore, progesterone and 17α-hydroxyprogesterone as endogenous steroids might induce PD-ECGF-related angiogenic potential in uterine endometrial cancer cells, but not MPA as a synthetic steroid. In conclusion, the failure of PD-ECGF induction by MPA might be the great merit of anti-angiogenic treatment with MPA for uterine endometrial cancers.

Cyanine-related compounds: a novel class of potent inhibitors of extraneuronal noradrenaline transport

The neurotransmitter noradrenaline is removed from the extracellular space by neuronal and extraneuronal transport mechanisms. In the past, further functional and biochemical characterisation of the corticosterone-sensitive extraneuronal transporter was hampered by the lack of highly potent inhibitors. Here we describe a new class of selective and highly potent inhibitors of the extraneuronal noradrenaline transporter. Clonal Caki-1 cells possess the human type of extraneuronal noradrenaline carrier. The effect of various steroids and steroid-like compounds on initial rates of specific 3H-noradrenaline transport in Caki-1 cells was investigated. None of these steroids had an inhibitory potency higher than that of corticosterone which hitherto was generally accepted as the most potent inhibitor of the extraneuronal noradrenaline transport. On the other hand, a variety of quinoline and isoquinoline derivatives interacted with the extraneuronal noradrenaline transporter. Several cationic quinolines that belong to the chemical class of the cyanine dyes turned out to be very potent inhibitors of 3H-noradrenaline transport in Caki-1 cells. The isocyanines, 1,1'-diisopropyl-2,4'-cyanine (disprocynium24) and 1-methyl-1'-isopropyl-2,4'-cyanine as well as the pseudoisocyanines 1,1'-diethyl-2,2'-cyanine (decynium22) and 1-isopropyl-1'-ethyl-2,2'-cyanine (iprecynium22) were most potent with IC50's of 14, 62, 16, and 18 nmol/l, respectively. The inhibitory potency on extraneuronal noradrenaline transport of 1-methyl-1'-isopropyl-2,4'-cyanine was determined also in isolated organs, namely the isolated incubated rabbit aorta and the isolated perfused rat heart.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of various steroids on the biosynthesis of arachidonic acid in isolated hepatocytes and HTC cells.

The effect of various steroids on the incorporation and desaturation of eicosa-8,11,14-trienoic acid in normal hepatocytes and HTC cells was investigated. After 3 hr incubation with 11-deoxycorticosterone, both kinds of cells showed an increase in the incorporation of eicosatrienoic acid. In contrast, progesterone, cortexolone, 17-beta-estradiol, testosterone, estriol, aldosterone, corticosterone, dexamethasone, dehydroepiandrosterone, 11-beta-hydroxyandrosterone, 11-ketoaetiocholanolone, epiaetiocholanolone and 5-beta-pregnane-3 alpha,20 alpha-diol, provoked no significant changes in the uptake of the exogenous acid. Of all the steroids tested, only 11-deoxycorticosterone, dexamethasone and 17-beta-estradiol evoked a significant inhibition on the arachidonate biosynthesis in both kinds of cells. Testosterone, estriol, aldosterone and corticosterone provoked a significant inhibition of delta 5-desaturase in HTC cells. In dexamethasone, this effect was dose-dependent (0 to 10(-4) M). Simultaneous incubation with 17-beta-estradiol or 11-deoxycorticosterone with dexamethasone led to an extent of inhibition on arachidonate biosynthesis that did not surpass the effect of each drug. Pretreatment of isolated hepatocytes with the antiglucocorticoid, cortexolone, prevented the dexamethasone-induced inhibition of arachidonate biosynthesis. Normal rat liver microsomes preincubated in vitro with dexamethasone, 11-deoxycorticosterone, 17-beta-estradiol, corticosterone or estriol (10(-6) or 10(-4) M concentration), showed no significant changes in the delta 5-desaturase activity. The results obtained suggest that the effect of the steroids on arachidonic acid biosynthesis in normal hepatocytes and HTC cells requires receptor occupancy and probably is mediated through a common biochemical mechanism.

Effects of steroids with different endocrine profiles on the development, morphology and function of the bursa of Fabricius in chickens

This paper describes the effect of various steroids on the anlage of the bursa of Fabricius in chickens. The steroids were administered by dipping embryonated eggs on the third day of incubation in ethanolic solutions of these steroids. The results with about 30 different steroids show that the capacity to inhibit the development of the bursa does not correlate with the endocrine properties of these steroids as measured in routine screening tests for androgenic, anabolic, progestational and oestrogenic activities or with the relative binding affinities for various endocrine receptors. More elaborate studies with several representative steroids show that testosterone (10 mg/ml), nandrolone (10 mg/ml), 11α-hydroxy-nandrolone (10 mg/ml), ethylestrenol (1 mg/ml), lynestrenol (1 mg/ml), and Org OD14 [tibolone] (0.1 mg/ml) induce also histomorphological changes in the remaining bursa tissue still present in 10 day-and 53-day old chickens and in the bursa-dependent sites of their spleens (53-day old chickens only). Testosterone and lynestrenol induced smaller changes than nandrolone or ethylestrenol. Tibolone and 11α-hydroxynandrolone were more effective than nandrolone. All drugs, except testosterone and lynestrenol, impaired antibody formation to Newcastle Disease Virus and decreased the serum levels of total IgG, but not of total IgM. Also these effects were not correlated with endocrine properties. In other studies (for references, see text) we found that several of these steroids, notably tibolone, favourably influence the course of spontaneous autoimmune diseases of NZB/W mice and Obese Strain chickens. Since this autoimmunosuppression is likely to be caused by inhibitory effects on bursa or bursa equivalent, we may use this approach for developing medically useful autoimmunosuppressive steroids with minimal endocrine effects.

Influence of certain steroids on lymphocyte transformation in sheep and goats studied in vitro.

The effect of various steroids on lymphocyte transformation was tested with peripheral blood lymphocytes (PBL) from sheep and goats. Transformation was induced with phytohaemagglutinin, pokeweed mitogen and Concanavalin A, and by allogeneic lymphocytes (mixed lymphocyte culture). Progestagens, androgens and corticosteroids inhibited mitogen-induced transformation of lymphocytes from both species. With sheep PBL, progestagens and androgens inhibited transformation at high concentrations. Progesterone and its less active metabolites 5 alpha-pregnanedione and 20 alpha-dihydro-progesterone were equally inhibitory. Corticosteroids were more effective than other steroids at concentrations of less than 1 mumol/l. Oestrogens had relatively little effect with the exception of diethylstilboestrol which markedly enhanced sheep PBL responses to mitogen. Structural comparisons suggested that the most suppressive C-19 and C-21 steroids possessed 4-en-3-one configuration in ring A, and that inhibitory activity was enhanced by C-17 alpha substitution as in 17 alpha-hydroxyprogesterone. The steroid effects on PBL were largely unaffected by the reproductive status of the donor, were exerted during the early pre-replicative phase rather than at the time of new DNA synthesis, and were not attributable to cytoxicity nor to changes in intracellular thymidine pools. An exception was found with the non-steroidal oestrogen, diethylstilboestrol, which enhanced the response to mitogen-treated cultures of sheep lymphocytes at both early and late phases of the cell cycle. It is concluded that several naturally occurring steroids affect the responsiveness of PBL to mitogenic stimuli, and that progesterone and/or certain of its metabolites may be effective in vivo when present at the high concentrations found in the utero-ovarian lymphatic network draining the gravid uterus or at the trophoblast-maternal interface in the sheep and goat.

Biphasic inhibition of bioactive hypothalamic corticotrophin releasing factor secretion in vitro by corticosterone and prevention of the second phase by various steroids.

The effect of various steroids on the functional activity of the rat hypothalamus in vitro was investigated. The addition of corticosterone (10(-7) mol/l) for 30 min to the incubation medium inhibited immediately the release of bioactive corticotrophin releasing factor (CRF) by tissue induced by serotonin (2.6 X 10(-8) mol/l). This was followed by a period lasting from 30 min (coincident with removal of the steroid from the medium) to 60 min when no inhibition was seen. Finally a second period of suppression of hypothalamic CRF activity in vitro was shown to be fully established 120 min after addition of the steroid. In more detailed investigations the latter inhibition was shown to occur when the tissue was exposed to the steroid (3 X 10(-7) mol/l) for 5 or 30 min, but not for 1 min, and it was dose-related. Of other steroids investigated, progesterone in high concentrations (3 X 10(-6 mol/l) suppressed to a small extent the functional activity of the hypothalamus in vitro but 17 alpha-hydroxyprogesterone, 11 alpha-hydroxyprogesterone, 11 alpha, 17 alpha-dihydroxyprogesterone and 11-epicortisol had no effect on the delayed inhibition. Progesterone (10(-7) mol/l) potentiated the ability of corticosterone (10(-8) mol/l) to induce the delayed suppression of hypothalamic CRF activity in vitro. In contrast, 17 alpha-hydroxyprogesterone, 11 alpha-hydroxyprogesterone, 11 alpha, 17 alpha-dihydroxyprogesterone and 11-epicortisol competitively antagonized this inhibitory action of corticosterone (3 X 10(-7) mol/l) in a dose-related manner (1.5 X 10(-8)-3 X 10(-8) mol/l). The action of the antagonist 11-epicortisol was similar whether it was added to the tissue in vitro before corticosterone or antagonist and agonist were added together. The functional characterization of steroid action on the hypothalamus may lead to a clearer understanding of the mechanism by which the compounds influence hormone release.

Inhibition of Cytokinin Action and of Heat/Aging Induced Potential for Cytokinin Action by Inhibitors of Membrane Synthesis and Function

Data to support the hypothesis that cytokinin action, in inducing the biosynthetic pathway involved in betacyanin synthesis in Amaranthus tri-color seedlings, is dependent on both membrane synthesis and function is presented. The experimental system included a pretreatment of heat shock (40 degrees C) and aging of cotyledon explants. This produced the conditions necessary for the full expression of cytokinin potential during the subsequent betacyanin induction. Cerulenin, an inhibitor of fatty acid and sterol synthesis, inhibited both the heat-induced potential for cytokinin action and the benzyladenine-dependent induction itself. This was also true of metyrapone, an inhibitor of hydroxylation reactions involving cytochrome P450. Gammexane, an inhibitor of phospholipid turnover, impaired the heat-induced process but not the benzyladenine-dependent betacyanin accumulation. This was also the case with 2-isopropyl-4-dimethylamino-5-methyl phenyl-1-piperidine carboxylate methyl chloride, an inhibitor of the cyclization steps in sterol and gibberellin synthesis. Filipin at 100 micrograms per milliliter inhibited both processes, particularly the heat-induced potential. The effect of various steroids and fatty acids on induction is recorded together with experiments aimed at using them to reverse some of the inhibitions. The effect of cerulenin on heat-induced potential was partially reversed by preparations of Amaranthus lipids. Some reversal of the filipin effects was obtained with beta-sitosterol and stigmasterol. It is concluded that menbrane synthesis is stimulated during the heat/aging pretreatment and during the induction and that some membrane function(s) is necessary for subsequent cytokinin action.

Steroid modulation of in vitro prostaglandin secretion by human thymic epithelium

The effect of adrenal and sex steroids on the thymus are well documented. Adrenalectomy and castration have been shown to increase the size of the thymus, whereas hormone administration induces atrophy. Increasing evidence suggests a role for prostaglandins in the immune response. Furthermore, it has been observed that steroids modulate prostaglandin (PG) production. We have studied the secretion of prostaglandins and the effect of various steroids on PG production in cultures of human thymus epithelial cells. Using reverse phase high pressure liquid chromatography and radioimmunoassay we have shown that these cells produced substantial amounts of PGE 2 and PGF 2z Dexamethasone decreased both PGE 2 and PGF 2z secretion in the cultures at 10 −7M. In most of the samples tested, testosterone (10 −7M) enhanced PGE 2 production whereas progesterone and estradiol (10 −7M) inhibited PGE 2 synthesis. The recent demonstration that thymic sex steroid receptors are likely to be located within the epithelium together with our finding that glucocorticoid-induced inhibition of prostaglandin secretion is mediated through an interaction with specific receptors suggest that the effects of sex steroids on prostaglandin secretion may well be a receptor-mediated process. The data suggest that prostaglandins represent one of the factors of the thymic environment involved in lymphocyte maturation, an assumption reinforced by the existence of prostaglandin receptors in lymphoid cells.

Prostaglandin secretion by human thymic epithelium: In vitro effects of steroids

Increasing evidence suggests a role for prostaglandins in the immune response. As steroids have been shown recently to modulate prostaglandin secretion, we have studied the secretion of prostaglandin and the effect of various steroids in culture of human thymus epithelial cells. Using reverse phase high pressure liquid chromatography and radioimmunoassays, we have shown that these cells produce substantial amounts of PGE 2 and PGE 2α and that this secretion is modulated by steroid hormones. Prostaglandin could represent one of the factors of the thymic environment which respond to steroid hormones.

On the inhibitory effect of some steroids on spermatogenesis in adult rainbow trout (Salmo gairdneri)

To test the antifertility effect of various steroids, fish were fed a diet containing steroids at two stages of the reproductive cycle: during spermatogenesis (June to November, experiment A) and during spermiation (November to February, experiment B). The fish in experiment A were given testosterone (T), methyltestosterone (MT), estradiol-17β (E2), hexestrol (H), progesterone (Pg), and FGA (Fluorogestone acetate) at doses of 0.05 and (or) 0.5 mg/kg of food. In experiment B, T, MT, and E2 were given at a dose of 0.5 mg/kg of food. The fish received a daily ration amounting to 1% of their body weight. In experiment A, inhibition of testicular growth was total with 0.5 mg MT and 0.5 mg E2 and partial with 0.5 mg T/kg of food. In these groups, there was no noticeable change in plasma gonadotropin (GTH) compared with the controls, except that the GTH rise observed in the other groups in September was prevented. This suggests that steroids act directly at the level of the gonad. In experiment B, no noticeable regression of the gonad occurred after steroid treatment. A big GTH rise was seen in the E2-treated group, but this was not followed by stimulation of spermiation. The total amount of sperm (50%) and spermatozoa collected during the experiment tended to be lower in the steroid-treated fish than in the controls. Spermatozoal fertilizing ability was significantly decreased (P < 0.005) by the testosterone treatment.

Kinetic studies of human endometrial hydroxysteroid dehydrogenase

Human endometrial hydroxysteroid dehydrogenase (HSD) in microsomal and mitochondrial fractions was characterized by the kinetic analysis of eight steroids: estradiol† (E 2), estrone (E 1), testosterone (T), androstenedione (A), 5-ene-androstene-3β,17β-diol (Adiol), dehydroepiandrosterone (D), 20α-dihydroprogesterone (20α-DHP) and progesterone (P). The enzyme activity was estimated from the initial rate of the formation of the product in the presence of various concentrations of [ 3H]-steroid and an excess amount of cofactor NAD for the oxidation and NADH for the reduction. The oxidation of E 2 had a smaller k m and a larger v max than the reduction of E 1, indicating that the enzyme favors oxidation. This observation correlates with the previous findings that in the intact cell the interconversion between E 2 and E 1 is favored toward the formation of E 1. The effect of various steroids on the rate of oxidation of E 2 and 20α-DHP was examined kinetically. The reaction was found to be competitively inhibited, suggesting that various HSD activities may derive from a single enzyme. The inhibitor constant, k i K, is similar to the k m value for each steroid. The relative k i values indicate that E 2 has the highest affinity to the enzyme followed in order by 20α-DHP, Adiol, T and A. The endometrial HSD in particulate fractions was treated with trypsin, phospholipase A 2 and detergents. The HSD activity was significantly lost after incubation with these enzymes, especially with phospholipase A 2, and detergents, indicating that HSD is tightly associated with the particulate components and the activity is stabilized by binding to the membrane.

Effect of glucocorticoids on cholesterol synthesis in isolated mouse thymocytes

Glucosteroids, as well as oxygenated derivatives of cholesterol, have been demonstrated to inhibit cholesterol biosynthesis in stimulated lymphocytes and Hela cells. We have therefore measured the effect of various steroids on the incorporation of [ 3H]-acetate into digitonin-precipitable material in mouse thymocytes. Dexamethasone, induces a marked inhibition of cholesterol synthesis (40–50% inhibition after 6 h incubation in the presence of 10 −6 M dexamethasone). This inhibitory effect appears specific of glucocorticoids as the other steroids tested (testosterone, estradiol, progesterone) are minimally effective. Moreover, the decrease in cholesterol synthesis produced by dexamethasone is abolished in the presence of Actinomycin D suggesting that the effects of steroids on cholesterol synthesis are mediated via glucocorticoid receptor occupancy and macromolecular synthesis. In contrast, human circulating lymphocytes and corticoresistant thymocytes do not show a significant inhibition of cholesterol synthesis in the presence of dexamethasone. As the rate of cholesterol synthesis is considered to represent a major factor controlling cell proliferation, our results suggest that part of the effects of glucosteroids on cell growth could result from an inhibition of cholesterol synthesis.

The effect of various steroids on corpus luteum function

The effect of seven steroids (d-norgestrel, R-5020, norethindrone, equilenin, megestrol acetate, estriol and R-2323) on corpus luteum function was assessed by their effect on the progesterone secretion rate of the autotransplanted ovary of the ewe. Only d-norgestrel (100 μg/h for 8 h) and R-5020 (100 μg/h for 8 h) proved effective in markedly suppressing progesterone output from the ovary.

In vitro manipulation of 2, 3-diphosphoglycerate levels in acid-citrate-dextrose blood with steroids

Erythrocyte 2, 3-DPG content has a marked effect on the oxyhemoglobin dissociation curve and is known to decrease in ACD stored blood. This study revealed the effect of various steroids on the level of 2, 3-DPG. Hydrocortisone sodium succinate and methylprednisolone sodium succinate were found to increase the levels of 2, 3-DPG in 3, 10, and 13 day old ACD stored blood during incubation. Hydrocortisone sodium succinate was more effective than methylprednisolone sodium succinate in increasing the level of 2, 3-DPG. In three day old blood the increased 2, 3-DPG approached the lower limits of normal values.

Effect of Various Steroids and ACTH on Distribution of Zoxazolamine in Rats

A study was performed on rats given pregnenolone-16α-carbonitrile (I), triamcinolone, fludrocortisone acetate, corticosterone, estradiol, or ACTH to investigate correlations between the in vivo effects upon zoxazolamine paralysis and the concentrations of this drug in plasma, brain, liver, kidney, heart, spleen, muscle, and fat. Pretreatment with the steroids or ACTH altered the organ concentrations of zoxazolamine but not the relationships between the interorgan concentrations. Protection by I was associated with a simultaneous reduction of zoxazolamine in plasma, brain, and most of the other organs (catatoxic mechanism) as compared with controls killed when paralysis disappeared in the pretreated group. The protective actions of ACTH and triamcinolone were often accompanied by high concentrations of zoxazolamine in plasma and most of the organs (syntoxic mechanism) when compared with controls sacrificed at spontaneous termination of the pharmacological response. Fludrocortisone seemed to protect through both phenomena. Corticosterone and estradiol were ineffective under the same conditions, eliciting no changes in the plasma clearance or organ concentrations of the drug.

Effect of various steroids on the hepatic glucuronidation and biliary excretion of bilirubin.

In rats, treatment with spironolactone or pregnenolone-16α-carbonitrile (PCN) accelerates bile flow and enhances hepatic microsomal bilirubin–UDP glucuronyltransferase activity (EC 2.4.1.17) and the biliary transport maximum (Tm) of bilirubin. The distribution of ethylanthranilate azo-pigments in fractions separated by thin-layer chromatography also indicates increased glucuronidation of bilirubin. These findings explain the mechanism of enhanced serum bilirubin disappearance in rats treated with the steroids.

Effect of Various Steroids and ACTH on Plasma Levels of Zoxazolamine and Dicumarol

Comparative experiments were performed on rats given pregnenolone-16α-carbonitrile, estradiol, progesterone, triamcinolone, hydroxydione, or ACTH (corticotropin) to study correlations between the in vivo conditioning effects upon resistance to zoxazolamine and dicumarol and the plasma concentrations of these drugs. The conditioners were classified as catatoxic when a decrease in toxicity was associated with increased blood clearance of the drug, and they were classified as syntoxic when in vivo protection was accomplished without a simultaneous fall in the plasma drug level. With these criteria, pregnenolone-16α-carbonitrile was markedly protective and catatoxic whereas triamcinolone and ACTH were moderately protective and syntoxic against zoxazolamine. The remaining steroids elicited very mild changes in zoxazolamine paralysis and blood clearance. Of all the conditioners tested, only estradiol protected against dicumarol intoxication and accelerated plasma clearance of this drug. Hence, only estradiol exhibited a manifest catatoxic effect against this anticoagulant.

Some biochemical effects of insulin and steroid hormones on the rat prostate in organ culture.

The effect of various steroids and insulin on expiants of the ventral prostate of adult rats in organ culture was investigated. Testosterone activated the incorporation of labeled precursors into RNA and protein and the formation of 14CO2 from 14C-glucose by expiants. All these effects were mimiced by insulin. The testosterone action was suppressed by cyproterone in vitro. In addition to androgens, glucocorticoids activated the incorporation of 3H-uridine into RNA. Simultaneous addition of testosterone with hydrocortisone or insulin produced an augmented effect on the incorporation of 3H-uridine into RNA which exceeded that resulting from a simple summation of the individual hormone responses. Insulin facilitated likewise the action of testosterone on the incorporation of 14C-amino acids into protein. When all three hormones were added simultaneously to the culture medium the stimulation of the three biochemical parameters was maximal. It was therefore concluded that all three hormones are necessary for an adequate maintenance of the ventral prostate of the rat.

Effect of various steroids and nonsteroidal microsomal enzyme inducers upon propoxyphene intoxication.

In rats, severe propoxyphene intoxication can be diminished more effectively by some catatoxic steroids than by known nonhormonal hepatic microsomal drug-metabolizing enzyme inducers, such as phenobar