contribution of nitric oxide on the relaxation effects of diethylstilbestrol

To evaluate the contribution of nitric oxide NO on the relaxation effects of diethylstilbestrol on rat uterus. Uterine rings from 8 nonpregnant Wistar Albino rats 300-350g in the pro-estrous phase were suspended in an organ bath and electrical field stimulation applied for recording isometric tension. The influence of NO on contractile responses of rat uterine rings was investigated. The effects of NO precursor L-arginine 10-7-10-4M concentration and NO synthase inhibitor L-nitro-arginine-methyl ester 10-7-10-4M concentration and a combination of them on contractile responses were studied in the presence and absence of diethylstilbestrol 2x10-4M concentration. The study was carried out at the Department of Pharmacology Laboratory, Faculty of Medicine, Dicle University, Diyarbakir, Turkey. Totally, 30 samples were investigated n=6 for each group, 5 groups. Diethylstilbestrol inhibited contractile responses 64.2 +/- 4.5% n=6, p<0.05. Contractile responses decreased in the presence of L-arginine n=6, p<0.05 and this inhibition was abolished in the presence of L-nitro-arginine-methyl ester n=6, p<0.05. The inhibition on contractile responses to diethylstilbestrol was potentiated in the presence of L-arginine under similar conditions n=6, p<0.05. The contractile responses to electrical field stimulation in the presence of diethylstilbestrol were not affected by L-nitro-arginine-methyl ester n=6, p>0.05. These data provide evidence that NO may potentiate the inhibitory effects of diethylstilbestrol by different mechanisms on the electrically induced contractions of the non-pregnant rat uterus

Compuestos disruptores endocrinos y su participación en la programación del eje reproductivo / Endocrine disruptor compounds and their role on the developmental programming of the reproductive axis

Different perturbations during fetal and post natal development unleash endocrine adaptations that permanently alter metabolism, increasing the susceptibility to develop later disease, process known as "developmental programming"'. Endocrine disruptor compounds (EDC) are widely spread on the environment and display estrogenic, anti-estrogenic or anti-androgenic activity; they are lypophilyc and stored for long periods on the adipose tissue. Maternal exposure to EDC during pregnancy and lactation produces the exposure of the fetus and neonate through placenta and breast milk. Epidemiological and experimental studies have demonstrated reproductive alterations as a consequence of intrauterine and/or neonatal exposure to EDC. Diethystilbestrol (DES) is the best documented compound, this synthetic estrogen was administered to pregnant women at the BO and 60 to prevent miscarriage. It was implicated in urogenital abnormalities in children exposed in utero and withdrawn from the market. The "DES daughters" are women with high incidence of vaginal hypoplasia, spontaneous abortion, premature delivery, uterine malformation, menstrual abnormalities and low fertility. The "DES sons" show testicular dysgenesis syndrome, which is characterized by hypospadias, cryptorchidism and low semen quality. This entity is also associated to the fetal exposure to anti-androgens as flutamide. The effects on the reproductive axis depend on the stage of development and the window of exposure, as well as the dose and the compound. The wide distribution of EDC into the environment affects both human health and ecosystems in general, the study of their mechanisms of action is extremely important currently.

Diversas perturbaciones durante el desarrollo fetal y posnatal desencadenan adaptaciones endocrinas que modifican permanentemente el metabolismo, incrementando la susceptibilidad para el desarrollo de enfermedades, proceso conocido como "programación durante el desarrollo". Los compuestos disruptores endocrinos (CDE) se encuentran en el medio ambiente y presentan actividad estrogénica, antiestrogénica o antiandrogénica; son altamente lipofílicos y se almacenan por periodos prolongados en el tejido adiposo. La exposición materna a CDE durante el embarazo y la lactancia permite su paso al producto a través de la placenta y la leche materna. Estudios epidemiológicos y experimentales han demostrado alteraciones en el eje reproductivo como consecuencia de la exposición intrauterina y/o neonatal a CDE. El compuesto mejor documentado es el dietilestilbestrol (DES), este estrógeno sintético fue administrado a mujeres embarazadas durante los 50s y 60s y retirado del mercado por su implicación en anormalidades urogenitales de los bebés expuestos in útero. Las denominadas "hijas del DES" son mujeres con alta incidencia de hipoplasia vaginal, malformaciones uterinas, irregularidades menstruales, baja fertilidad y alta prevalencia de aborto espontáneo y parto prematuro. Por su parte, "los hijos del DES" presentan una entidad clínica conocida como síndrome de disgenesia testicular caracterizado por hipospadias, criptorquidia y baja calidad del semen. Este síndrome también se asocia a la exposición fetal a compuestos antiandrogénicos como la ñutamida. Los efectos en el eje reproductivo dependen del estadio de desarrollo y del tiempo de exposición, así como de la dosis y el compuesto del que se trate. La extensa presencia de CDE en el ambiente afecta la salud humana e impacta al ecosistema en general por lo cual es de suma importancia el estudio de los mecanismos involucrados en su acción.

Effects of endocrine disrupting chemicals on expression of phospholipid hydroperoxide glutathione peroxidase mRNA in rat testes

Phospholipid hydroperoxide glutathione peroxidase(PHGPx), an antioxidative selenoprotein, is modulated byestrogen in the testis and oviduct. To examine whetherpotential endocrine disrupting chemicals (EDCs) affectthe microenvironment of the testes, the expression patternsof PHGPx mRNA and histological changes were analyzedin 5-week-old Sprague-Dawley male rats exposed to severalEDCs such as an androgenic compound [testosterone (50,200, and 1,000microg/kg)], anti-androgenic compounds [flutamide(1, 5, and 25mg/kg), ketoconazole (0.2 and 1mg/kg), anddiethylhexyl phthalate (10, 50, and 250mg/kg)], andestrogenic compounds [nonylphenol (10, 50, 100, and 250mg/kg), octylphenol (10, 50, and 250mg/kg), and diethyl-stilbestrol (10, 20, and 40microg/kg)] daily for 3 weeks via oraladministration. Mild proliferation of germ cells andhyperplasia of interstitial cells were observed in the testesof the flutamide-treated group and deletion of thegerminal epithelium and sloughing of germ cells wereobserved in testes of the diethylstilbestrol-treated group.Treatment with testosterone was shown to slightly decreasePHGPx mRNA levels in testes by the reverse transcription-polymerase chain reaction. However, anti-androgeniccompounds (flutamide, ketoconazole, and diethylhexylphthalate) and estrogenic compounds (nonylphenol,octylphenol, and diethylstilbestrol) significantly up-regulated PHGPx mRNA in the testes (p<0.05). Thesefindings indicate that the EDCs might have a detrimentaleffect on spermatogenesis via abnormal enhancement ofPHGPx expression in testes and that PHGPx is useful as abiomarker for toxicity screening of estrogenic or anti-androgenic EDCs in testes.

Effects of steroid hormones on total brain Na(+)-k+ ATPase activity in Oreochromis mossambicus.

The effects of administration of cortisol, corticosterone, testosterone, progesterone and a synthetic estrogen. diethylstilbestrol (DES) on total brain Na(+)-K+- ATPase were investigated in tilapia, O. mossambicus. Exogenous administration of 0.125 and 0.25 microg/g body weight of glucocorticoids and 0.125, 0.25 and 0.5 microg/g body weight of DES for 5 days significantly stimulated Na+(-) K+ ATPase activity by 14-41% in the brain, while 0.5 microg/g body weight of glucocorticoids did not evoke any response on the activity of the enzyme. Progesterone (0.125 and 0.25 microg/g body weight) administration significantly decreased the enzyme activity by 21-36% and high dose (0.5 microg/g body weight) was ineffective. Testosterone exhibited a biphasic effect on Na(+)-K+ ATPase activity--a low dose stimulated by 14% while middle and high doses inhibited it by 19-24%. The results seem to be the first report on the effect of steroids on brain ATPase activity in a teleost. When 0.25microg/g body weight of actinomycin D or puromycin was administered prior to the treatment of similar doses of hormones, the inhibitors significantly inhibited the effect of the hormones by 24-52%. This clearly shows that the effect of the hormones was sensitive to the action of inhibitors suggesting a possible genomic mode of action under long-term treatment. The results suggest that cortisol, corticosterone and DES may possibly stimulate the co-transport of glucose and excitation of membrane potential while progesterone and testosterone inhibit them in the brain of O. mossambicus by regulating the activity of Na(+)-K+ ATPase.

Influence of steroid hormones on plasma proteins in freshwater tilapia Oreochromis mossambicus.

The effect of administration of cortisol, corticosterone, testosterone, progesterone and a synthetic estrogen, diethylstilbestrol on plasma proteins of tilapia (Oreochromis mossambicus) was investigated. SDS-PAGE clearly revealed the appearance of several new bands of protein, which were not present in the control plasma and were comparable to the known bands of the molecular markers. Of the different bands appeared in the steroids treated plasma, the most important ones were the presumed vitellogenin and corticotrophin binding globulin with a molecular weight of 180 and 17 kDa, respectively. Increase in protein bands in the steroid treated plasma of O. mossambicus confirmed the anabolic role of steroids in teleost.

The effect of spironolactone on the rat uterus.

Our experimental study showed that in a dose related manner SP has successful inhibitory effect on the rat uterine horn, and also on the smooth muscle organs; ileum and trachea. We guess that SP can be used in well regulated dosed with least side effects to arrest preterm labor on human being in the future. Up to date there is no manuscript about contraction inhibitory effect of SP on the uterus. We hope this study will be of scientific help.

Efectos de estrógenos y andrógenos sobre la esteroidogénesis de células de granulosa de ratas inmaduras en condiciones de cultivo / Effects of estrogens and andorgens on the steroidogenesis of granulosa cells of immature rats in culture conditions

Estudiamos el efecto de la androstenediona y del dietilestilbestrol sobre la secreción de esteroides de células de granulosa de ratas inmaduras, para ello empleamos cultivos primarios de estas células y métodos de análisis radioinmunológicos. Se encontró que el dietilestilbestrol no fue capaz de modificar la esteroidogénesis ni en condiciones basales ni en condiciones estimuladas por la hormona estimulante del folículo. La androstenediona produjo un incremento en la secresión de estradiol y la de progesterona dependiente de la concentración del andrógeno y del tiempo de incubación. El efecto de este andrógeno sobre la secreción de progesterona fue sinérgico en relación con las acciones de la hormona estimulante del folículo. Estos resultados sugieren que en este modelo experimental los estrógenos no parecen desempeñar el papel de reguladores

Hormônios anabolizantes em alimentos: aspectos analíticos / Anabolic hormones in foods: analytical aspects

Desde a década dos setenta o uso de hormônios como promotores de crescimento em animais de criaçäo tem sido proibido em vários países, inclusive no Brasil. Para o controle destes anabolizantes foi desenvolvida uma enorme variedade de métodos, tanto como propósitos de triagem como de confirmaçäo. Os métodos mais usados säo os físico-químicos, tais como cromatografia em camada delgada, cromatografia a gás acoplada a espectrômetro de massa, cromatografia líquida de alto desempenho com detector UV, ou ensaios imunoquímicos, tais como radioimunoensaio ou enzimaimunoensaio. Este artigo tem por finalidade revisar os métodos analíticos mais usados internacionalmente no controle de substâncias anabolizantes em tecidos e urina de animais criados para consumo humano. Atençäo especial é dada ao anabolizante potencialmente carcinogênico Dietilstibestrol (DES) em relaçäo à sua toxicocinética, dinámica, seu possível uso no Brasil e às dificuldades envolvidas em sua determinaçäo

Uterine and placental 5-HT profile in different gestational period of albino rats.

Possible role of 5-HT in pregnancy was investigated in albino rats by biological estimation of uterine and placental 5-HT contents in different periods of gestation in normal and drug treated rats. Uterine 5-HT level increased steadily from day-1 of gestation to reach the peak on day-7; thereafter, the level continued to decline throughout the period till day-20 when 5-HT level was lowest. From day-20, a mild secondary rise started and remained persistent even after parturition. The results show that a critical level of 5-HT in early gestational period is necessary for conception. Manipulation of endogenous 5-HT do not influence duration of gestation.

Synergistic promoter effect of diethylstilbesterol & phenobarbitone in diethylnitrosamine induced hepatic neoplasia in rats.

An experimental model was designed to study the role of both diethylstilbesterol (DES) and phenobarbitone (PB) singly or in combination, in diethylnitrosamine (DEN) induced hepatic neoplasia. Experimental and control rats were injected DEN (200 mg/kg) or saline, ip. Acute morphological changes were studied at days 1, 2 and 3; and at weekly intervals for 3 wk. Four weeks after DEN pretreatment the experimental and control rats were randomized into various groups and fed DES (T1), PB (T2) or a combination of both DES and PB (T3). Five rats from each experimental group were sacrificed at 10, 20 and 30 wk. Group T3 showed gross nodules with a mean nodule score of 20.5 mm at 20 wk. Nodule score in T1, T2 and T3 at 30 wk were 7, 9 and 34.5 mm respectively. The sequential morphological lesions encountered were clear cell and acidophilic foci; acidophilic, basophilic and mixed nodules. Haemorrhage within the nodules was frequent when DES was administered either alone or in combination with PB. Oval cell proliferation and cholangiocellular lesions were produced in all experimental groups. Foci and nodules generally showed loss of glucose-6 phosphatase, adenosine triphosphatase and invariable presence of gamma-glutamyl transpeptidase and glycogen. A combination of DES and PB as promoter yielded earliest and highest nodule score. This suggests that DES and PB acted synergestically as promoters or that PB caused enzyme induction thereby enhanced the promotive effect of DES.

Radiometric detection of metabolic activity of Paracoccidioides brasiliensis and its susceptibility to amphotericin B and diethylstilbestrol

A paracoccidiodomicose (blastomicose sul-americana) é uma doença sistêmica muito mais freqüente no sexo masculino, causada pelo fungo dimórfico Paracoccidioides brasiliensis. Um sistema radiométrico foi utilizado para estudar a atividade metabólica e o efeito de drogas sobre este fungo "in vitro". A forma Y do fungo, cultivada em Sabouraud líquido, foi inoculada em frascos estéreis contendo o meio aeróbio 6B, juntamente com 2,0 uCi de substâncias marcadas com carbono-14. Frascos-controle, preparados da mesma foram inoculados com fungos autoclavados. Para estudar os efeitos da anfotericina B (AB) (0,1 e 10 microng/ml) e do dietilestilbestrol (DEB) (1,5 e 10 microng/ml), controles adicionais foram preparados, contendo fungos viáveis mas näo a droga. Todos os frascos foram incubados a 35-C e o metabolismo medio diariamente com uma máquina Bactec. A produçäo de CO2 pelo P.brasiliensis foi lenta e pôde ser acompanhada por 50 dias. Concentraçöes de 10 microng/ml de AB e 5 microng/ml de DEB inibiram o metabolismo e tiveram efeito fungicida. Os resultados com DEB poderiam explicar a baixa incidência da doença em mulheres. Esta técnica é promissora para estudar as vias metabólicas, investigar substâncias marcadas mais adequadas para tornar mais rápida a detecçäo radiométrica do fungo e para acompanhar os efeitos de outras drogas e fatores sobre o metabolismo do P.brasiliensis "in vitro" (

Fibrosis y cirrosis en el conejo por acción del dietilestilbestrol y su inhibición por la progesterona / Fibrosis and cirrhosis in the rabbit induced by diethylestilbestrol and its inhibition with progesterone

El dietilestilbestrol administrado por boca en forma prolongada (más de tres meses) produce en conejos una intensa fibrosis o cirrosis hepática. Se investigó el efecto de la progesterona inyectada en forma intramuscular día por medio (33 mg) respecto a esta fibrosis hormonal. Se estudiaron cuatro lotes de conejos. En el primero (lote A) compuesto por once conejos, se administró el estrógeno, se realizaron biopsias quirúrgicas seriadas y se comprobó la existencia de fibrosis después de los tres meses de iniciado el estrógeno. Al suspender el dietilestilbestrol la fibrosis desapareció paulatinamente hasta que no era histológicamente comprobable a los ocho meses de la suspensión. En el segundo (lote B) se administró conjuntamente el dietilestilbestrol y la progesterona en nueve conejos. El estudio histológico demostró que la progesterona impedía totalmente o disminuía la formación del tejido conectivo. El tercero (lote C) estaba compuesto por trece conejos, ocho recibieron dietilestilbestrol durante un período de cuatro a doce meses y sirvieron de testigos a cinco conejos que recibieron dietilestilbestrol durante seis meses, y a éstos sin suspender el estrógeno, se les añadió progesterona. Los conejos se sacrificaron a los cuatro meses y a los nueve meses de recibir la progesterona. Se comprobó que la fibrosis era mucho menor que en los conejos que no habían recibido progesterona. Se hicieron tambíen mediciones de enzimas, bilirrubina, etc., a todos los lotes sin que se comprobaran alteraciones con respecto a los valores normales, y se realizó también el estudio histológico de conejos que habían recibido solamente progesterona en forma prolongada sin encontrar anormalidades. Se concluye que en la fibrosis y cirrosis producida en conejos por la administración prolongada de dietilestilbestrol, la progesterona administrada simultáneamente impide totalmente o disminuye al mínimo el aumento del tejido conectivo. Administrada una vez producida la fibrosis y sin eliminar el estrógeno, la progesterona disminuye el aumento del tejido conectivo provocado por el dietilestilbestrol

Enhanced platelet aggregation by oral contraceptives: effect of PG synthetase inhibitors.

Platelet aggregation time was significantly (P less than 0.01) decreased in female rabbits treated with oral contraceptive (a preparation containing low dose of estrogen) as also by injection of diethylstilbestrol (10 mg/kg), while in animals that received indomethacin (10 mg/kg) or aspirin (30 mg/kg) (PG synthetase inhibitors) along with oral contraceptives or diethylstilbestrol there was no significant alteration in platelet aggregation time. The increased synthesis of prostaglandins or some of the intermediary product like TXA2 might be responsible for this effect.