Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 9 de 9
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Folia Biol (Praha) ; 67(2): 76-81, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34624940

RESUMO

The aim of this in vitro study was to examine the dose-dependent effects of iron as a potential endocrine disruptor in relation to the release of sexual steroid hormones by a human adrenocortical carcinoma (NCI-H295R) cell line. The cells were exposed to different concentrations (3.90, 62.50, 250, 500, 1000 µM) of FeSO4.7H2O and compared with the control group (culture medium without FeSO4.7H2O). Cell viability was measured by the metabolic activity assay. Quantification of sexual steroid production was performed by enzyme-linked immunosorbent assay. Following 48 h culture of the cells in the presence of FeSO4.7H2O, significantly (P < 0.001) increased production of progesterone was observed at the lowest concentration (3.90 µM) of FeSO4.7H2O, whereas the lowest release of progesterone by NCIH295R cells was noted after addition of 1000 µM of FeSO4.7H2O, which did not elicit cytotoxic action (P > 0.05). Testosterone production was substantially increased at the concentrations ≤ 62.50 µM of FeSO4.7H2O. Lower levels of testosterone were recorded in the groups with higher concentrations (≥ 250 µM) of FeSO4.7H2O (P > 0.05). The presented data suggest that iron has no endocrine disruptive effect on the release of sexual steroid hormones, but its toxicity may be reflected at other points of the steroidogenesis pathway.


Assuntos
Neoplasias do Córtex Suprarrenal , Carcinoma Adrenocortical , Técnicas de Cultura de Células , Linhagem Celular Tumoral , Humanos , Ferro
2.
Physiol Res ; 69(5): 871-883, 2020 11 16.
Artigo em Inglês | MEDLINE | ID: mdl-32901497

RESUMO

Nickel is a ubiquitous environmental pollutant, which has various effects on reproductive endocrinology. In this study, human adrenocortical carcinoma (NCI-H295R) cell line was used as an in vitro biological model to study the effect of nickel chloride (NiCl2) on the viability and steroidogenesis. The cells were exposed to different concentrations (3.90; 7.80; 15.60; 31.20; 62.50; 125; 250 and 500 microM) of NiCl2 and compared with control group (culture medium without NiCl2). The cell viability was measured by the metabolic activity assay. Production of sexual steroid hormones was quantified by enzyme linked immunosorbent assay. Following 48 h culture of the cells in the presence of NiCl2 a dose-dependent depletion of progesterone release was observed even at the lower concentrations. In fact, lower levels of progesterone were detected in groups with higher doses (>/=125 microM) of NiCl2 (P<0.01), which also elicited cytotoxic action. A more prominent decrease in testosterone production (P<0.01) was also noted in comparison to that of progesterone. On the other hand, the release of 17beta-estradiol was substantially increased at low concentrations (3.90 to 62.50 microM) of NiCl2. The cell viability remained relatively unaltered up to 125 microM (P>0.05) and slightly decreased from 250 microM of NiCl2 (P<0.05). Our results indicate endocrine disruptive effect of NiCl2 on the release of progesterone and testosterone in the NCI-H295R cell line. Although no detrimental effect of NiCl2 (

Assuntos
Neoplasias do Córtex Suprarrenal/patologia , Carcinoma Adrenocortical/patologia , Estradiol/metabolismo , Níquel/farmacologia , Progesterona/metabolismo , Testosterona/metabolismo , Neoplasias do Córtex Suprarrenal/metabolismo , Carcinoma Adrenocortical/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular , Disruptores Endócrinos/farmacologia , Humanos , Técnicas In Vitro
3.
Folia Biol (Praha) ; 62(1): 34-9, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27085008

RESUMO

Exogenous substances altering the function of the endocrine system and exhibiting adverse health effects on the organism are defined as endocrine disruptors. Nonylphenol is one of the most abundant alkylphenol ethoxylate derivatives, being detected in food products. Diverse studies have classified nonylphenol as hazardous to the health, especially to male reproduction. This in vitro study aimed to examine the effects of 4-nonylphenol on androstenedione and testosterone production as well as on the viability of Leydig cells of NMRI mice. The cells were cultured for 44 h with addition of 0.04; 0.2; 1.0; 2.5 and 5.0 µg/ml of 4-nonylphenol and compared to the control. Quantification of testosterone and androstenedione directly from aliquots of the medium was performed by enzyme-linked immunosorbent assay. Cell viability was measured by the metabolic activity assay for mitochondrial functional activity. Androstenedione production significantly (P < 0.001) increased with 1.0; 2.5 and 5.0 µg/ml 4-nonylphenol. Although cAMP-stimulated testosterone production was not significantly affected by 4-nonylphenol, a tendency to attenuate the level of testosterone in the Leydig cells treated with 2.5 and 5.0 µg/ml 4-nonylphenol was observed. The viability of mouse Leydig cells was slightly increased at the lowest doses of 4-nonylphenol (0.04 and 0.2 µg/ml). We also observed an increase at higher concentrations of the substance (1.0; 2.5 and 5.0 µg/ml), but this increase was not significant. Further investigations are required to establish the biological significance and possible reproductive implications.


Assuntos
Hormônios/biossíntese , Células Intersticiais do Testículo/citologia , Fenóis/farmacologia , Androstenodiona/biossíntese , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , AMP Cíclico/metabolismo , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Camundongos , Testosterona/biossíntese
4.
J Toxicol Environ Health A ; 62(5): 349-58, 2001 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-11261897

RESUMO

The purpose of this investigation was to study the effectiveness of two nickel-binding amino acids, histidine (His) and cysteine (Cys), to prevent the inhibitory action of Ni2+ on testosterone (T) production by mouse primary Leydig cell culture. The maximal human chorionic gonadotropin (hCG)-stimulated T response was measured by radioimmunoassay (RIA) in the culture media. Three types of experiments were performed. In a concentration-response study, Ni2+ (62.5 to 1,000 microM) was added to the cells simultaneously with equimolar or twice the equimolar concentrations of His or Cys and the cultures were maintained for 48 h. Nickel-induced reduction in T production was completely prevented by equimolar concentrations of His at Ni2+ concentrations of 125, 250, and 500 microM; equimolar or twice the equimolar concentrations of His were only partially effective at 1,000 microM Ni2+. Protective action of Cys was complete only at the lowest concentration of Ni2+ (125 microM). In a second series, the cells were incubated for various times (0.5 to 48 h) with 1,000 microM Ni2+ in the presence of 2,000 microM His or Cys. Increasing the time of incubation, the protective effect of both amino acids against Ni2+ was reduced. In a third series, attempts were made to reverse the action of 1,000 microM Ni2+ after incubation with cells for various times (0.5 to 24 h), followed by exposure to 2,000 microM His or Cys. Cell cultures were maintained for 48 h. A partial recovery of hCG-stimulated T production could be observed only if the amino acid was added not later than 4 h after the metal. This time was also required to elicit the T depression produced by Ni2+. Administration of either His or Cys at later times had no effect. Our results show that both His and Cys are able to moderate the effects of Ni2+ on Leydig cell T production, depending on the concentration of this metal ion, as well as on amino acid. However, at higher Ni2+ concentrations the complete protection by His or Cys is only temporary. Administration of these amino acids after the Ni2+-produced decrease in T production was not able to reverse the process.


Assuntos
Aminoácidos/farmacologia , Células Intersticiais do Testículo/efeitos dos fármacos , Células Intersticiais do Testículo/metabolismo , Níquel/antagonistas & inibidores , Níquel/toxicidade , Testosterona/biossíntese , Animais , Células Cultivadas , Quelantes/farmacologia , Cisteína/farmacologia , Relação Dose-Resposta a Droga , Histidina/farmacologia , Masculino , Camundongos , Camundongos Endogâmicos , Radioimunoensaio , Fatores de Tempo
5.
Environ Res ; 80(4): 340-7, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10330307

RESUMO

Postblastocyst development of mouse preembryos was studied in vitro in order to determine direct effect of Cd2+, Ni2+, and Co2+ ions on embryogenesis during the peri-implantation stage. Uterine horns were flushed on Day 4 of pregnancy and expanded blastocysts were cultured for 4 days in the presence of micromolar Cd2+ (1.1-26.4), Ni2+ (0. 1-500) or Co2+ (1-200). Area of trophoblast outgrowth was measured and used as a quantitative toxicological endpoint. Hatching, attachment, outgrowth, and formation of inner cells mass were also registered. Significant adverse effect on the development stages were observed at 2.2 microM (Cd2+), at 10 microM (Ni2+), and at 100 microM (Co2+). Cd2+ and Co2+ decreased the area of trophoblast markedly at concentrations of 1.1 and 10 microM, respectively. Ni2+ exposure resulted in a slight increase at 10 microM followed by a marked reduction in the trophoblast area at 250 microM. Reduced proliferative ability of trophoblast cells may point to compromised invasiveness of the embryo. The lowest Cd2+ concentration (1.1 microM=0.25 microg/ml) significantly deteriorating trophoblast development was found to be lower than Cd levels ranging up to 0.512 microg/g, reported in clinical ovarian samples of occupationally nonexposed women. The morphological alteration and loss of cellular contacts in blastocysts induced by exposure to Cd2+, Ni2+, or Co2+ may adversely influence adhesion and recognition events and may disturb aggregation of mononuclear trophoblastic cells to multinucleated cells in the course of peri-implantation in vivo as well.


Assuntos
Blastocisto/efeitos dos fármacos , Cádmio/toxicidade , Cobalto/toxicidade , Níquel/toxicidade , Animais , Blastocisto/citologia , Diferenciação Celular/efeitos dos fármacos , Divisão Celular/efeitos dos fármacos , Técnicas de Cultura , Relação Dose-Resposta a Droga , Implantação do Embrião/efeitos dos fármacos , Feminino , Camundongos , Camundongos Endogâmicos , Gravidez , Fatores de Tempo , Trofoblastos/citologia , Trofoblastos/efeitos dos fármacos
6.
Bioelectromagnetics ; 19(7): 429-31, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9771586

RESUMO

This study evaluated the effect of sinusoidal 50 Hz magnetic field on the basal and human chorionic gonadotropin (hCG)-stimulated testosterone (T) production of 48-h mouse Leydig cell culture. The luteinizing hormone (LH) analog hCG was used to check the T response of the controls and to evaluate the possible effect of the applied magnetic field on the steroidogenic capacity of the exposed cells. Leydig cells were obtained from the testes of 35- to 45-g CFLP mice and isolated by mechanical dissociation without enzyme treatment. The cell cultures were exposed to sinusoidal 50 Hz 100 microT (root mean square) AC magnetic field during the entire time of a 48-h incubation. Testosterone content of the culture media was measured by radioimmunoassay. In cultures exposed to the magnetic field, a marked increase of basal T production was found (P < .05), compared with the unexposed controls, whereas no significant difference was seen between the exposed or unexposed cultures in the presence of maximally stimulating concentration of hCG. These findings demonstrate that sinusoidal 50 Hz 100 microT magnetic fields are able to stimulate the basal T production of primary mouse Leydig cell culture, leaving the steroidogenic responsiveness to hCG unaltered.


Assuntos
Gonadotropina Coriônica/farmacologia , Células Intersticiais do Testículo/metabolismo , Magnetismo , Testosterona/biossíntese , Animais , Células Cultivadas , Humanos , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos , Radioimunoensaio , Testículo/citologia
7.
J Toxicol Environ Health A ; 55(3): 213-24, 1998 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-9772104

RESUMO

This study evaluated the effects of Ni2 on testosterone (T) production of mouse Leydig cells in vitro following an in vivo or in vitro exposure. CFLP mice were subjected to repeated exposure (4 treatments, subcutaneously, every 3 d) to 10, 20 or 40 mg/kg body weight of NiSO4 or 1.0 ml of 0.9% NaCl solution. Depressed human chorionic gonadotropin (hCG)-stimulated T response was seen over a 48-h culture of testicular interstitial cells obtained from the animals exposed to 20 mg/kg or higher dose of NiSO4, while the basal T production remained unaltered. There were no Ni2+-related changes in the body weights or in the weights of testes, epididymides, adrenals, and kidneys. No histopathological alteration was found in the examined organs of NiSO4-treated groups except the dose-dependent tubular lesions in kidney as a result of a specific rather than a general cytotoxic action. To assess the direct effect of Ni2+ on Leydig-cell T production, testicular interstitial cells were cultured with Ni2+ (62.5 to 1000 microM) for 48 h in the presence or absence of maximally stimulating concentration of hCG. Dose-dependent depression in hCG-stimulated T production was seen at 125 microM or higher dose of Ni2+, while basal T production was unaffected. In order to evaluate the time dependency of this effect the cells were cultured for various times in the presence or absence of 250 and 1000 microM Ni2+. Decreased hCG-stimulated T production was found in the cultures maintained at least for 4 h in the presence of 1000 microM Ni2+, whereas at 250 microM at least 16 h was required to elicit the depression. Cell viability was assessed by a metabolic activity (MTT) assay. The viability of cells was unaltered by 250 microM Ni2+, and only a slight decrease was found even at the end of the 48-h culture period in the presence of 1000 microM Ni2+. Our results show a dose-related depression in stimulated T production of mouse Leydig cells in culture following either in vivo or in vitro Ni2+ treatment at a dose that does not induce any general toxic or significant cytotoxic action. The data of the time-course study indicate that the effect of Ni2+ on Leydig-cell T production is both time and concentration dependent, and not due to cytotoxicity.


Assuntos
Células Intersticiais do Testículo/efeitos dos fármacos , Níquel/toxicidade , Testosterona/biossíntese , Animais , Cálcio/metabolismo , Células Cultivadas , Relação Dose-Resposta a Droga , Células Intersticiais do Testículo/metabolismo , Masculino , Camundongos
8.
J Appl Toxicol ; 17(5): 321-7, 1997.
Artigo em Inglês | MEDLINE | ID: mdl-9339745

RESUMO

Cadmium (Cd) is able to decrease preovulatory luteinizing hormone (LH) levels in blood and inhibit ovulation in rats. In this study the direct effects of Cd on steroidogenesis in granulosa cells were investigated. The cells obtained from ovarian follicular aspirates of 41 women undergoing in vitro fertilization (IVF) were cultured. Cadmium-induced alterations in the cellular morphology and in the production of progesterone by the cells was determined after exposure to concentrations of 8, 16, 32 and 64 microM CdCl2 for 2, 4, 8, 24 and 48 h. Progesterone secretion by granulosa cells could be stimulated with increasing concentrations of follicle-stimulating hormone (FSH). Combined effects of Cd and FSH were also studied. Cadmium diminished progesterone production in unstimulated and FSH-supported cells depending on its concentration and the exposure time. Follicle-stimulating hormone (100 ng ml[-1]) protected against Cd-induced suppression of progesterone production. Cadmium interfered with cell-cell junctions and the adherence of cells. No protective effect of FSH on Cd-induced alteration in cell morphology could be observed. Retraction of cytoplasmic extensions occurred at a lower dose and within a shorter exposure than a decrease in progesterone production. In conclusion, Cd exerted a direct effect on both granulosa cell morphology and on steroid biosynthesis. The lowest Cd concentration (16 microM) that was able to reduce progesterone production was about 3.5 times higher than levels reported in the ovary of a female smoker. The presented data can help to define environmental, occupational and life-style (smoking) risk factors in gonadal function during the preconception period of the female reproductive lifespan.


Assuntos
Cádmio/toxicidade , Células da Granulosa/efeitos dos fármacos , Progesterona/biossíntese , Adulto , Células Cultivadas , Relação Dose-Resposta a Droga , Feminino , Hormônio Foliculoestimulante/administração & dosagem , Células da Granulosa/citologia , Células da Granulosa/metabolismo , Humanos , Hormônio Luteinizante/biossíntese , Ciclo Menstrual/efeitos dos fármacos , Fatores de Risco
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...