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1.
Toxicol Ind Health ; 39(5): 237-247, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36951826

RESUMO

There is considerable evidence that Bisphenol S (BPS) induces various toxicological effects and is an industrial health issue. However, little data are available on the in vivo effects of BPS on the liver, a major target of drug toxicity. In this study, we evaluated the potential harmfulness of low levels of BPS in the liver of male mice. Also, we investigated the interaction between BPS and peroxisome proliferator-activated receptor-gamma (PPARγ) by computational docking approach. PPARγ is a member of the superfamily of nuclear hormone receptors. It acts as a transcription factor and regulates the genes involved in lipid and glucose metabolism and in inflammation and necrosis. Mice were exposed to BPS, in drinking water at 25, 50, and 100 µg/kg for 10 weeks. The protocol was started after weaning. At the time of sacrifice, blood samples were collected for a biochemical analysis, followed by liver tissue collection for histopathological study. Results showed that BPS-induced hypertriglyceridemia, increased liver injury markers, and initiated histopathological changes, including inflammatory cell infiltration, hepatocellular necrosis, and steatosis. BPS did not affect glycated hemoglobin (HbA1C). Interestingly, data showed that BPS could interact with the PPARγ ligand-binding pocket by hydrogen bonds with Asn 219, Cys 276, Ser 280, and Thr 283. We suggest that PPARγ is among the targets of BPS and could play a key role in the cascade reaction of BPS-induced liver disruption. These findings support the hypothesis that the post-weaning period is sensitive to low-dose BPS exposure that can lead to dyslipidemia signature later in life.


Assuntos
Fígado , PPAR gama , Masculino , Animais , Camundongos , PPAR gama/genética , Inflamação/metabolismo , Necrose
2.
J Cell Physiol ; 237(7): 3057-3068, 2022 07.
Artigo em Inglês | MEDLINE | ID: mdl-35561261

RESUMO

Bisphenol S (BPS) is a common substitute of bisphenol A (BPA). Recent data suggest that BPS acts as an obesogenic endocrine disruptor with emerging implications in the physiopathology of metabolic syndrome. However, the effects of BPS on monocarboxylate transporters (acting as carriers for lactate, pyruvate, and ketone bodies) and the mitochondrial respiratory system in the liver remain limited. For this purpose, male Swiss mice were treated with BPS at 100 µg/kg/day for 10 weeks, in drinking water. An increase in body weight and food intake was observed with no increase in locomotor activity. Moreover, data show that BPS increases hepatic MCT1 (a key energetic fuel transporter) mRNA expression accompanied by hepatic steatosis initiation and lipid accumulation, while disrupting mitochondrial function and oxidative stress parameters. Furthermore, BPS produced a significant increase in lactate dehydrogenase and creatine kinase activities. We can suggest that BPS contributes to hepatic steatosis in mice by upregulating monocarboxylate transporters and affecting the bioenergetic status characterized by an impaired mitochondrial respiratory system. Thus, our data highlight a new mechanism putatively implicated in hepatic steatosis development during BPS-induced obesity involving lactate metabolism.


Assuntos
Compostos Benzidrílicos , Fígado Gorduroso , Animais , Compostos Benzidrílicos/toxicidade , Fígado Gorduroso/induzido quimicamente , Fígado Gorduroso/genética , Lactatos , Masculino , Camundongos , Mitocôndrias , Sistema Respiratório , Regulação para Cima
3.
Ecotoxicology ; 31(7): 1087-1095, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35838932

RESUMO

Bisphenol S (BP-S) is one of the most important substitutes of bisphenol A (BP-A), and its environmental occurrence is predicted to intensify in the future. Both BP-A and BP-S were tested for adverse effects on early life stages of Arbacia lixula sea urchins at 0.1 up to 100 µM test concentrations, by evaluating cytogenetic and developmental toxicity endpoints. Embryonic malformations and/or mortality were scored to determine embryotoxicity (72 h post-fertilization). It has been reported in academic dataset that bisphenols concentration reached µg/L in aquatic environment of heavily polluted areas. We have chosen concentrations ranging from 0.1-100 µM in order to highlight, in particular, BP-S effects. Attention should be paid to this range of concentrations in the context of the evaluation of the toxicity and the ecological risk of BP-S as emerging pollutant. Cytogenetic toxicity was measured, using mitotic activity and chromosome aberrations score in embryos (6 h post-fertilization). Both BP-A and BP-S exposures induced embryotoxic effects from 2.5 to 100 µM test concentrations as compared to controls. Malformed embryo percentages following BP-A exposure were significantly higher than in BP-S-exposed embryos from 0.25 to 100 µM (with a ~5-fold difference). BP-A, not BP-S exhibited cytogenetic toxicity at 25 and 100 µM. Our results indicate an embryotoxic potential of bisphenols during critical periods of development with a potent rank order to BP-A vs. BP-S. Thus, we show that BP-A alternative induce similar toxic effects to BP-A with lower severity.


Assuntos
Arbacia , Poluentes Químicos da Água , Animais , Arbacia/genética , Compostos Benzidrílicos , Análise Citogenética , Embrião não Mamífero , Fenóis , Ouriços-do-Mar/genética , Poluentes Químicos da Água/toxicidade
4.
Ecotoxicol Environ Saf ; 161: 459-466, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29909315

RESUMO

Since 2010, Bisphenol A (BPA), an endocrine disruptor has been restricted and replaced by analogues like Bisphenol S (BPS). However, little is known about BPS effects and growing concern have suspected the "BPA-free" Label. Several recent studies suggest that BPS is associated with increased risk of diabetes and obesity. However, the underlying mechanisms remain unidentified. The current study investigates investigate BPS effects on hypothalamic neuropeptides regulating feeding behavior, either orexigenic or anorexigenic in Swiss Albino mice. We also studied the effect of BPS on the apelinergic system (apelin/apelin receptor (APJ)) as an original physiological system with pleiotropic actions. Bisphenol S at 25, 50, 100 µg/kg was administered to mice in water drink for 10 weeks started after weaning. Our results showed that BPS exposure alters orexigenic hypothalamic neuropeptide (AgRP) regulating feeding behavior but not anorexigenic neuropeptides (POMC, CART). Such orexigenic alterations may underlay appetite disorders leading to a concomitant food intake and body weight gain increase. In addition, data show that BPS affects the hypothalamic apelinergic system. We found a significant decrease in APJ mRNA but not in apelin expression. Based on hypothalamic APJ distribution, we suggested a potent specific physiological alteration of this receptor in mediating neuroendocrine responses in hypothalamus. Thus, our findings provide that BPS exposure could contribute to the development of obesity and metabolic disorders.


Assuntos
Apelina/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Neuropeptídeos/metabolismo , Fenóis/toxicidade , Sulfonas/toxicidade , Animais , Receptores de Apelina/metabolismo , Compostos Benzidrílicos , Peso Corporal , Comportamento Alimentar/efeitos dos fármacos , Hipotálamo/metabolismo , Masculino , Camundongos , Proteínas do Tecido Nervoso/metabolismo , Neuropeptídeos/genética , Obesidade/induzido quimicamente , Pró-Opiomelanocortina/metabolismo , RNA Mensageiro/metabolismo , Aumento de Peso
5.
Reprod Toxicol ; 107: 104-111, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34838688

RESUMO

A wide variety of environmental chemicals/xenobiotics including bisphenol A (BPA) has been shown to cause male reproductive dysfunctions and infertility. Recently, bisphenol S (BPS) replaces BPA, in several products, including foodstuffs, under the BPA-free label. However, several studies have raised inquietude about the potential adverse effects of BPS. The present study was conducted to evaluate sperm parameters, biochemical parameters, mitochondrial function, and histopathological patterns after post-lactation BPS exposure at a low dose. Male rats (21 days old) were exposed to water containing BPS at 50 µg/L in drinking water for 10 weeks. Results showed no significant alteration in the gonadosomatic index (GSI) and relative reproductive organs weight. However, a significant reduction in epididymal sperm parameters (number, viability, and mobility) with morphological abnormalities were observed in the BPS group compared to control. An increase of malondialdehyde (MDA) level accompanied by antioxidant defense alteration particularly, in glutathione peroxidase activity, as well as a defective mitochondrial function were observed in testicular tissues of BPS treated rats. More importantly, in histopathological diagnosis, BPS treatment induces hypospermatogenesis and alteration in Sertoli cells. In silico docking studies illustrated BPS binds with steroidogenic acute regulatory (StAR) protein thereby affecting the transport of cholesterol into mitochondria resulting in decreased steroidogenesis. These results reflect a reprotoxic effect of BPS vould potentially lead to fertility reduction, in sexually maturity age. We highlighted that post-lactation exposure to BPS, equivalent in humans to the period covering childhood and adolescent stages, disrupt male reproduction function.


Assuntos
Poluentes Ambientais/toxicidade , Mitocôndrias/efeitos dos fármacos , Oligospermia/induzido quimicamente , Fenóis/toxicidade , Fosfoproteínas/metabolismo , Sulfonas/toxicidade , Animais , Antioxidantes/metabolismo , Masculino , Malondialdeído/metabolismo , Oligospermia/metabolismo , Oligospermia/patologia , Ratos Wistar , Contagem de Espermatozoides , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testículo/metabolismo , Testículo/patologia
6.
J Physiol Biochem ; 66(4): 271-81, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20694542

RESUMO

Nitric oxide (NO) is a short-lived radical that functions as a neurotransmitter in the central nervous system and plays a physiological role in the regulation of hypothalamic-pituitary-adrenal axis and vasopressinergic axis. In the present study, we aimed to investigate the interaction between the generation of NO and vasopressin (AVP) and corticosterone release after 3 days of water deprivation in rats. Animals were previously treated with intraperitoneal (i.p.) saline or L-nitro-arginine methyl ester (L-NAME) injection. L-NAME is a nonspecific inhibitor of nitric oxide synthases. In control rats given i.p. saline or L-NAME, hypothalamic, pituitary, and plasma AVP levels and plasma corticosterone did not change from baseline levels (p>0.05). Three days of water deprivation increased significantly the corticosterone levels in plasma (p<0.01) and AVP levels in hypothalamus and plasma (p<0.01), but not in pituitary, which showed a significant decrease. These variations were concomitant with the elevation of nitrates/nitrates in plasma. L-NAME injection abolished significantly (p<0.01) the elevation of plasma corticosterone and hypothalamic AVP levels induced by water deprivation. These findings showed that in water-deprived rats, nitric oxide synthase inhibition by L-NAME inhibits corticosterone and vasopressin release, suggesting a potent stimulatory role of NO.


Assuntos
Corticosteroides/metabolismo , Óxido Nítrico Sintase/antagonistas & inibidores , Vasopressinas/metabolismo , Animais , Peso Corporal , Encéfalo/patologia , Hematócrito , Hipotálamo/metabolismo , Masculino , NG-Nitroarginina Metil Éster/farmacologia , Neurotransmissores/química , Óxido Nítrico/química , Prostaglandinas/metabolismo , Ratos , Ratos Wistar , Vasopressinas/química , Água/química
7.
Food Chem Toxicol ; 132: 110670, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31301325

RESUMO

Bisphenol A has been restricted in a large variety of products. Bisphenol S (BPS) is its major substitute. Yet, the impacts of BPS on the central nervous system are unknown, especially in vulnerable populations like children. The aim of this study was to investigate the effects of BPS on behavioral performances and the expression of cerebral monocarboxylate transporters (MCTs). Male Swiss mice were exposed to BPS at 100 µg/kg in drinking water for 10 weeks. The protocol started after the lactation period, which is a sensitive period of early social-emotional development. Elevated T-maze and open field tests were used to measure respectively, anxiety-related and activity-related behaviors. Molecular expressions of MCTs isoforms (MCT1, MCT2, MCT4) were determined in the frontal cortex. Data showed that BPS does not affect mRNA expression of MCTs. However, BPS decreases the number of entries into the open arms and the time spent on them for BPS-treated mice. These data reveal an anxiogenic effect of BPS. For locomotor activity and exploratory behavior levels, differences did not reach a statistically significant level in the BPS-exposed group. The effect of BPS on behavioral performances unravels a putative risk for psychopathology development in early childhood and calls for more attention.


Assuntos
Comportamento Animal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Transportadores de Ácidos Monocarboxílicos/metabolismo , Fenóis/farmacologia , Sulfonas/farmacologia , Animais , Encéfalo/metabolismo , Masculino , Camundongos , Transportadores de Ácidos Monocarboxílicos/genética , RNA Mensageiro/genética
8.
Environ Sci Pollut Res Int ; 26(4): 3636-3642, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30523531

RESUMO

Bisphenol S, an industrial chemical, has raised concerns for both human and ecosystem health. Yet, health hazards posed by bisphenol S (BPS) exposure remain poorly studied. Compared to all tissues, the intestine and the liver are among the most affected by environmental endocrine disruptors. The aim of this study was to investigate the molecular effect of BPS on gene expression implicated in the control of glucose metabolism in the intestine (apelin and its receptor APJ, SGLT1, GLUT2) and in the liver (glycogenolysis and/or gluconeogenesis key enzymes (glucose-6-phosphatase (G6Pase) and phosphoenolpyruvate carboxykinase (PEPCK)) and pro-inflammatory cytokine expression (TNF-α and IL-1ß)). BPS at 25, 50, and 100 µg/kg was administered to mice in water drink for 10 weeks. In the duodenum, BPS exposure reduces significantly mRNA expression of sodium glucose transporter 1 (SGLT1), glucose transporter 2 (GLUT2), apelin, and APJ mRNA. In the liver, BPS exposure increases the expression of G6Pase and PEPCK, but does not affect pro-inflammatory markers. These data suggest that alteration of apelinergic system and glucose transporters expression could contribute to a disruption of intestinal glucose absorption, and that BPS stimulates glycogenolysis and/or gluconeogenesis in the liver. Collectively, we reveal that BPS heightens the risk of metabolic syndrome.


Assuntos
Regulação da Expressão Gênica/efeitos dos fármacos , Glucose/genética , Absorção Intestinal/efeitos dos fármacos , Fenóis/toxicidade , Sulfonas/toxicidade , Animais , Apelina/genética , Apelina/metabolismo , Receptores de Apelina/genética , Receptores de Apelina/metabolismo , Gluconeogênese/efeitos dos fármacos , Gluconeogênese/genética , Glucose/metabolismo , Transportador de Glucose Tipo 2/genética , Transportador de Glucose Tipo 2/metabolismo , Glucose-6-Fosfatase/genética , Interleucina-1beta/metabolismo , Absorção Intestinal/genética , Intestinos/efeitos dos fármacos , Intestinos/fisiologia , Fígado/efeitos dos fármacos , Fígado/fisiologia , Masculino , Camundongos , Transportador 1 de Glucose-Sódio/genética , Transportador 1 de Glucose-Sódio/metabolismo , Fator de Necrose Tumoral alfa/genética , Fator de Necrose Tumoral alfa/metabolismo
9.
C R Biol ; 331(9): 655-62, 2008 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-18722984

RESUMO

The aim of this study was the evaluation of the hepatic damages following a subchronic exposure to malathion, an organophosphorus (OP) insecticide. Malathion was administered intragastrically in 1 ml corn oil containing 100 mg/kg Body Weight daily for 32 days. Malondialdehyde (MDA) concentration superoxide dismutase (SOD) and catalase (CAT) activities were analysed using a non-denaturing electrophoresis. The serum activities of Pseudocholinesterase (PchE), aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) were determined. Malathion exposure leads to a significant decrease in AchE activity, an increase in hepatic MDA, and in serum ASAT and ALAT activities. A positive correlation between serum transaminases levels and hepatic MDA was demonstrated. These results indicate that malathion exposure induced lipid peroxidation LPO, a process of degradation of membrane lipids, involving the deterioration of the cellular integrity. We have recorded a slight increase in antioxidant enzymes activities. This leads us to suggest an insufficient elimination of free radicals, causing cytotoxic effects.


Assuntos
Catalase/metabolismo , Doença Hepática Induzida por Substâncias e Drogas/enzimologia , Inseticidas/toxicidade , Malation/toxicidade , Superóxido Dismutase/metabolismo , Alanina Transaminase/sangue , Animais , Aspartato Aminotransferases/sangue , Butirilcolinesterase/metabolismo , Catalase/genética , Eletroforese em Gel de Poliacrilamida , Peroxidação de Lipídeos/efeitos dos fármacos , Testes de Função Hepática , Masculino , Ratos , Ratos Wistar , Superóxido Dismutase/genética
10.
Toxicology ; 250(1): 27-31, 2008 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-18588939

RESUMO

It has been confirmed that organophosphorus compounds OP altered glucose homeostasis. Considerable experimental and clinical evidences have contributed the beneficial effects of polyphenol molecules on metabolic homeostasis. However, up to date limited studies have been performed on this topic. The aim of this study was to evaluate whether caffeic acid, an active phenolic component was able to reduce metabolic disruption induced by malathion administration. Malathion at 100mg/kg was administered to rats alone or in combination with caffeic acid at100 mg/kg. Malathion decreases hepatic GP activity and increases HK activity accompanied with a rise in the hepatic glycogen rate. Moreover, coadministration of malathion with caffeic acid resulted in restoration of malathion-induced GP inhibition and HK1 increase. These results may be due to the significant increase recorded in acetylcholinesterase (AchE) activity in vivo after coadministration of malathion and caffeic acid. Indeed, malathion is known to inhibit AChE activity leads to subsequent activation of cholinergic receptor that increased in part, catecholamine and glucocorticoids secretion; provoked glycogenolysis and gluconeogenesis activation. Thus, we can suggest that increase's (AchE) activity seems to be responsible for caffeic acid restoration on malathion-induced metabolic disruptions. Recent studies support the hypothesis that oxons bind to a secondary site on acetylcholinesterase, leading to activation/inhibition of the catalytic site. Thus, caffeic acid or its derivates may be leading to activation of the catalytic site within the second site interaction.


Assuntos
Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Inibidores da Colinesterase/toxicidade , Fígado/efeitos dos fármacos , Malation/toxicidade , Acetilcolinesterase/efeitos dos fármacos , Acetilcolinesterase/metabolismo , Animais , Glicogênio/metabolismo , Glicogênio Fosforilase/efeitos dos fármacos , Glicogênio Fosforilase/metabolismo , Hexoquinase/efeitos dos fármacos , Hexoquinase/metabolismo , Inseticidas/toxicidade , Fígado/metabolismo , Masculino , Ratos , Ratos Wistar
11.
C R Biol ; 330(2): 143-7, 2007 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-17303541

RESUMO

This study investigates the effects of subchronic exposure to organophosphate insecticide Malathion (Fyfanon 50 EC 500 g/l) of commercial grade. It was administered intragastrically by stomach tube in the amount of 1 ml of corn oil containing 100 mg/kg body weight (BW) daily for 32 days. At the end of the experiment, acetylcholinesterase activity (AChE), haematocrit value, haemoglobin content, and blood glucose concentration were estimated. The liver and the skeletal muscle were removed to determine hepatic and muscular glycogen, hepatic proteins and lipids contents. No sign of toxicity was observed until the end of experiment. No significant change in the haematocrit value was observed, in spite of the significant increase in haemoglobin content, which can be considered as an adaptive situation in order to guarantee a good oxygenation in response to pulmonary damage induced following subchronic exposure to organophosphorus compound. Malathion intoxication decreased significantly hepatic proteins and lipid contents that could be associated to liver gluconeogenesis. This result was coupled with a significant decrease in muscular glycogen rate, which indicates a stimulated glycogenolysis in favour of glucose release into the blood until reaching hyperglycaemia. Several studies indicate that hyperglycaemia is temporary, which is probably due to a stimulated glycogenesis that increases hepatic glycogen deposition and return of glucose to control levels, as demonstrated in our study. One possible explanation for these results could be the turnover of glucose by a succession between its release via glycogenolysis and gluconeogenesis, which involves abnormal hyperglycaemia, and its storage via glycogenesis in subchronic exposure to malation.


Assuntos
Inibidores da Colinesterase/toxicidade , Gluconeogênese/efeitos dos fármacos , Glicogenólise/efeitos dos fármacos , Malation/toxicidade , Acetilcolinesterase/análise , Animais , Glicemia/análise , Hematócrito , Hemoglobinas/análise , Inseticidas/toxicidade , Lipídeos/análise , Fígado/química , Fígado/efeitos dos fármacos , Pulmão/efeitos dos fármacos , Masculino , Músculo Esquelético/química , Músculo Esquelético/efeitos dos fármacos , Proteínas/análise , Distribuição Aleatória , Ratos , Ratos Wistar
12.
Life Sci ; 80(11): 1033-9, 2007 Feb 20.
Artigo em Inglês | MEDLINE | ID: mdl-17258234

RESUMO

The involvement of oxidative stress in the pathogenesis of alcoholic diseases in the liver has been repeatedly confirmed. Resveratrol, a natural phytoalexin present in grape skin and red wine possesses a variety of biological activities including antioxidant. This study was conducted to evaluate whether resveratrol has a preventive effect on the main indicators of hepatic oxidative status as an expression of the cellular damage caused by free radicals, and on antioxidant defence mechanism during chronic ethanol treatment. Wistar rats were treated daily with 35% ethanol solution (3 g/kg/day i.p.) during 6 weeks and fed basal diet or basal diet containing 5 g/kg resveratrol. Control rats were treated with i.p. saline and fed basal diet. Experimentally, chronic ethanol administration leads to hepatotoxicity as monitored by the increase in the level of hepatic marker enzymes and the appearance of fatty change, necrosis, fibrosis and inflammation in liver sections. Ethanol also enhanced the formation of MDA in the liver indicating an increase in lipid peroxidation, a major end-point of oxidative damage, and caused drastic alterations in antioxidant defence systems. Particularly the activities of hepatic superoxide dismutase (SOD), glutathione peroxidase (GPx) and catalase (CAT) were found reduced by ethanol treatment while glutathione reductase (GR) activity was unchanged. Dietary supplementation with resveratrol during ethanol treatment inhibited hepatic lipid peroxidation and ameliorated SOD, GPx and CAT activities in the liver. Conclusively, we can suggest that resveratrol could have a beneficial effect in inhibiting the oxidative damage induced by chronic ethanol administration, which was proved by the experiments that we conducted on rats.


Assuntos
Antioxidantes/administração & dosagem , Depressores do Sistema Nervoso Central/farmacologia , Etanol/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Estilbenos/administração & dosagem , Animais , Catalase/metabolismo , Dieta , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Injeções Intraperitoneais , Peroxidação de Lipídeos/efeitos dos fármacos , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Masculino , Malondialdeído/metabolismo , Ratos , Ratos Wistar , Resveratrol , Superóxido Dismutase/metabolismo
13.
Toxicology ; 223(1-2): 9-14, 2006 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-16621213

RESUMO

The aim of this study was the evaluation of the effects of a subchronic exposure to malathion, an organophosphorus (OP) insecticide, on plasma glucose and hepatic enzymes of glycogenolysis and glycolysis in rats in vivo. Malathion was administered intragastrically by stomach tube in the amount of 1 ml corn oil containing 100mg/kg body weight (BW) daily for 32 days. At the end of the experiment, the liver was removed. The activities of glycogen phosphorylase (GP) and hexokinase (HK) were analysed in the homogenate. The methodology employed was a non-denaturing electrophoresis followed by activity-staining (native PAGE). Malathion decrease GP activity by 50% and increase HK activity by 10%. In addition, an hepatomegaly was recorded with a rise in the hepatic glycogen rate in malathion-treated rats. Moreover, subchronic administration of malathion has no effect on blood glucose concentration. The storage of glycogen in liver may be due to a stimulation of insulin secretion after the inhibition of acethylcholinesterase activity in pancreatic beta cells by malathion. These findings were in favour of an activation of glycogen storage by malathion.


Assuntos
Glicogênio Fosforilase/metabolismo , Glicogênio/metabolismo , Hexoquinase/metabolismo , Inseticidas/toxicidade , Fígado/efeitos dos fármacos , Malation/toxicidade , Administração Oral , Animais , Glicemia/metabolismo , Peso Corporal/efeitos dos fármacos , Eletroforese em Gel de Poliacrilamida , Fígado/enzimologia , Fígado/metabolismo , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar
14.
C R Biol ; 328(5): 463-70, 2005 May.
Artigo em Francês | MEDLINE | ID: mdl-15948635

RESUMO

Metabolic and endocrine effects of water and/or food deprivation in rats. We aim at studying the effect of water deprivation, food deprivation and their combination for three days on adrenal cortex, pituitary-thyroid axis and vasopressinergic system activity in rats. Corticosterone level was determined by fluorimetric method. The levels of free thyroxine (FT4) and thyroid stimulating hormone (TSH) were determined by immunoenzymatic assay and vasopressin (AVP) level was determined by radio-immunoassay. In all three groups, basal levels of plasma corticosterone were increased. A thyroid dysfunction was shown after water deprivation, food deprivation and their combination reflected by a significant decrease in FT4 levels. Paradoxically, a significant decrease in TSH level was observed in food-deprived rats and in rats subjected to simultaneous food and water deprivation, while a slight and not significant decrease in TSH level was shown in water-deprived rats. A significant increase in plasma AVP level was observed after water deprivation and simultaneous water and food deprivation, while no change was found after food deprivation. The data indicated that water deprivation, food deprivation and their combination stimulated the adrenal cortex, thereby suggesting a stress state. On the other hand, it seems that nutritional stress modifies the pituitary-thyroid axis through mechanisms different from those of osmotic stress. Moreover, it seems that food deprivation partially prevented the stimulatory effect of water deprivation on vasopressinergic system.


Assuntos
Privação de Alimentos , Privação de Água , Córtex Suprarrenal/fisiologia , Animais , Masculino , Ratos , Ratos Wistar , Tireotropina/sangue , Tiroxina/sangue
15.
Environ Sci Pollut Res Int ; 22(8): 6198-207, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25404496

RESUMO

Exposure to pesticides is suspected to cause human health problems. Our study aimed to evaluate preventive effects of caffeic acid (3,4-dihydroxycinnamic acid) in the hypothalamus against malathion-induced neuropeptides gene expression alterations. Malathion at 100 mg/kg was administered intragastrically to rats alone or in combination with caffeic acid at 100 mg/kg during 4 weeks. A molecular expression of hypothalamic neuropeptides and plasmatic cholinesterase activity was investigated. Furthermore, we used in silico analysis, known as computational docking, to highlight the nature of acetylcholinesterase-malathion/caffeic acid interactions. Our findings showed differences in the responses and indicate that caffeic acid reversed malathion-induced decrease in corticotropin-releasing hormone mRNA but not brain-derived neurotrophic factor which presented an increased tendency. We suggest that caffeic acid can interact with acetylcholinesterase as the primary target of organophosphorus compounds. Results predict that caffeic acid can block partly the acetylcholinesterase gorge entrance via π-π stacking interaction with Tyr 124 and Trp 286 residues of the peripheral site leading to its stricture. Under this condition, we suggested that acetylcholine trafficking toward the catalytic site is ameliorated compared to malaoxon according to their sizes.


Assuntos
Antioxidantes/farmacologia , Ácidos Cafeicos/farmacologia , Inseticidas/toxicidade , Malation/toxicidade , Neuropeptídeos/metabolismo , Acetilcolinesterase/metabolismo , Animais , Inseticidas/metabolismo , Malation/análogos & derivados , Malation/metabolismo , Masculino , Ratos
16.
C R Biol ; 327(1): 12-20, 2004 Jan.
Artigo em Francês | MEDLINE | ID: mdl-15015751

RESUMO

Effect of dehydration on nitric oxide, corticotropic and vasopressinergic axis in rat. The purpose of our work is to study, in the male 'Wistar' rat, the effects of a chronic dehydration, by deprivation of water for three days out of four, during four repeated cycles, on the evolution of certain blood variables, on the activities of both corticotropic and vasopressinergic axis and on the synthesis of nitric oxide. The chronic dehydration causes a considerable reduction of the body weight, an activation of the vasopressinergic axis and an increase in the circulating rates of the nitrates/nitrites, which represent the final metabolites of the reaction of oxidation of nitric oxide. The pituitary-adrenal axis is not statistically affected by the chronic dehydration. This seems to be in favour of a possible adaptation of corticotropic axis to chronic water deprivation. The activation of synthesis of nitric oxide shows its implication in the regulation of the water balance and its buffer effect on vasoconstriction and hypertension induced by water stress.


Assuntos
Hormônio Adrenocorticotrópico/metabolismo , Arginina Vasopressina/metabolismo , Desidratação/metabolismo , Óxido Nítrico/metabolismo , Animais , Doença Crônica , Masculino , Ratos , Ratos Wistar
17.
Tunis Med ; 82(8): 717-24, 2004 Aug.
Artigo em Francês | MEDLINE | ID: mdl-15532765

RESUMO

The aim of our work was to study the developmental changes in plasma and hepatic concentrations of carbohydrates, lipids, and proteins in "Wistar" rats between prepartum day 1 (fetus considered J-1) and postpartum day 133 (adult considered j+133). In addition, the evolution of insulinemia has been examined. The 21 day aged fetus (j-1), as compared to the adult (j+133) showed a lower glycemia, a higher stock of hepatic glycogen, lower rates of lipids and proteins in the plasma and in the liver. The fetal insulinemia was significantly higher than adult's. After the delivrance we have attended to an increase of the glycemia and a very marked depletion of the glycogenic stock in the liver. The plasma and hepatic lipids and proteins rose after birth. The insulinemia fell considerably and reached the lowest level. Between the 14th and 30th day of the postnatal life, a restoration of the stock of the hepatic glycogen, a normal glycemia, an elevation of the plasma and hepatic rates of proteins, and a decrease of the lipidic levels in plasma and liver were recorded. In addition the concentration of insulin increased during this period. All these values remained steady during the adult stage. We conclude that the development of rats is accompanied with several metabolic and hormonal changes. These are particularly marked at birth and weaning.


Assuntos
Envelhecimento/metabolismo , Insulina/fisiologia , Animais , Animais Recém-Nascidos/metabolismo , Desenvolvimento Fetal , Ratos
18.
Environ Int ; 64: 83-90, 2014 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24382480

RESUMO

Bisphenol-A (BPA) is one of the highest volume chemicals produced worldwide, with over 6billion pounds produced and over 100t released into the atmosphere each year. Recent extensive literature has raised concerns about its possible implication in the etiology of some human chronic diseases such as diabetes, obesity, reproductive disorders, cardiovascular diseases, birth defects, chronic respiratory and kidney diseases and breast cancer. In this review, we present the highlighted evidences on the relationship between BPA exposure and human chronic diseases and we discuss its eventual mechanisms of action, especially genetic, epigenetic and endocrine disruption mechanisms with the possible involvement of oxidative stress, mitochondrial dysfunction and cell signaling.


Assuntos
Compostos Benzidrílicos/efeitos adversos , Distúrbios Induzidos Quimicamente , Doença Crônica , Poluentes Ambientais/efeitos adversos , Fenóis/efeitos adversos , Exposição Ambiental , Humanos
19.
Food Chem Toxicol ; 48(6): 1473-7, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20233601

RESUMO

Exposure to organophosphate (OP) pesticides is virtually ubiquitous. These inevitable agents are neurotoxicants, but recent evidence also points to lasting effects on carbohydrate metabolism. The aim of this study was to investigate the effects of 32 repeated treatment days with malathion, an OP insecticide, on some molecular and metabolic parameters. Malathion at 100 mg/kg was administered by gavage in Wistar rats. Results of this study indicate a significant decrease in hypothalamic corticotropin-releasing hormone mRNA, of malathion-treated rats. This result, in accordance with that of diabetic type 2 rat model, may be due to very potent negative feedback effects of glucocorticoids on hypothalamo-pituitary-adrenal (HPA) axis activity. In addition, we have recorded a significant increase in hypothalamic inducible NO synthase mRNA which probably enhances the negative feedback. These alterations are accompanied with hypertriglyceridemia that may be a favourable condition to insulin resistance. Thus, results of the present study suggest that malathion can be considered as an important risk factor in the development of diabetes type 2, which prevalence increased substantially in our country and around the world. Clearly, we need to focus further research on the specific incidences of hazardous food chemical contaminant that might be contributing to epidemic health perspectives.


Assuntos
Dislipidemias/induzido quimicamente , Regulação da Expressão Gênica/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Malation/toxicidade , Animais , Hormônio Liberador da Corticotropina/genética , Hipotálamo/metabolismo , Óxido Nítrico Sintase Tipo I/genética , Óxido Nítrico Sintase Tipo II/genética , Reação em Cadeia da Polimerase , RNA Mensageiro/genética , Ratos , Ratos Wistar
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