RESUMO
Although many countries banned the insecticide endosulfan, it is still an environmental pollutant. Plants metabolize the two diastereomers of the formulations known as technical grade endosulfan (TGE) by two phase I pathways: hydrolysis leading to less toxic derivatives and oxidation giving endosulfan sulfate which is as toxic as endosulfan itself. We assessed the removal, bioaccumulation and phase I metabolization of TGE from water matrices using hairy root clones (HRs) of three edible species, Brassica napus, Raphanus sativus and Capsicum annuum. B. napus and C. annuum HRs removed 86% of TGE from the bioreaction media in 2 and 96 h, respectively, whereas R. sativus HRs removed 91% of TGE within 6 h of biotreatment. In the experiments with B. napus, only endosulfan sulfate was detected in both biomass and medium, whereas R. sativus and C. annuum accumulated endosulfan sulfate and endosulfan alcohol. Besides, endosulfan lactone was detected in C. annuum reaction medium. Acute ichthyotoxicity assays toward Poecilia reticulata showed that media contaminated with TGE lethal levels did not produce mortality after the phytotreatments. This research highlights the feasibility of using HRs to evaluate plant enzymatic abilities toward xenobiotics and their potential for the design of ex situ decontamination processes.
Assuntos
Endossulfano , Inseticidas , Endossulfano/análise , Endossulfano/metabolismo , Endossulfano/toxicidade , Biodegradação Ambiental , Inseticidas/análise , Inseticidas/metabolismo , Inseticidas/toxicidade , ÁguaRESUMO
Cellular and humoral responses were evaluated in Litopenaeus vannamei juveniles when exposed to malathion, endosulfan, and their mixture. Each experiment was performed in the hemolymph collected at each exposure time (5 and 96â¯h) in duplicate; total hemocyte count, coagulation time, hemocyanin concentration, phenoloxidase (PO) and superoxide dismutase (SOD) activities were quantified. Survival was not affected by pesticides applied individually and mixed. Clotting time did not show significant differences concerning increase of concentration percentage of the pesticides tested. In organisms exposed to the pesticide mixture, hemocyanin decreased at 5â¯h of exposure as the concentration increased. Only in the malathion experiment did exposed shrimp to 10 and 50% of the LC50-96â¯h show significantly (pâ¯<â¯0.05) higher hemocyte contents. For malathion, significantly (pâ¯<â¯0.05) lower PO values in shrimp exposed to higher concentrations (10 and 50% of the LC50-96â¯h) were determined. While for the mixture treatment, high SOD value was determined at high exposure time and concentration. Malathion was the pesticide that showed an effect on some variables even at sublethal concentrations. The Continuous Concentration Criteria of the United States Environmental Protection Agency did not represent effects on the variables when they were compared with the averages of the control group.
Assuntos
Endossulfano/toxicidade , Imunidade Celular/efeitos dos fármacos , Imunidade Humoral/efeitos dos fármacos , Malation/toxicidade , Penaeidae/efeitos dos fármacos , Animais , Sinergismo Farmacológico , Hemocianinas/sangue , Hemócitos/efeitos dos fármacos , Hemócitos/imunologia , Hemolinfa/efeitos dos fármacos , Hemolinfa/imunologia , Monofenol Mono-Oxigenase/metabolismo , Penaeidae/imunologiaRESUMO
The surface used for agricultural production in Argentina significantly increased in recent years, mainly due to the expansion of soybean crops. As a result, the use of agrochemicals increased too. Many natural populations of Caiman latirostris (broad-snouted caiman) are affected by habitat fragmentation and the constant exposure to pesticides. This exposure could produce Reactive Oxygen Species. The negative imbalance between ROS generation and the capacity of the biological systems to eliminate the reactive intermediaries or avoid the damage is called Oxidative Stress. The aim of this study was to evaluate oxidative damage and antioxidant defense in C. latirostris hatchlings after in ovo exposure to widely used pesticide formulations. Embryos were exposed by topical exposure on the eggshell, from the beginning of incubation period, to sub-lethal concentrations of two glyphosate formulations: PanzerGold® (PANZ) and Roundup® Full II (RU): 500, 750, 1000⯵g/egg; to the endosulfan (END) formulation Galgofan® and the cypermethrin (CYP) formulation Atanor®: 1, 10, 100, and 1000⯵g/ egg. Blood samples were taken to all animals immediately after hatching for the application and comparison of the following oxidative stress biomarkers between the exposed groups and their respective controls: lipoperoxidation through thiobarbituric acid reactive substances (TBARS), DNA base oxidation through the modified comet assay, and the activities of Catalase (CAT) and Superoxide dismutase (SOD) in erythrocytes. Our results showed lipoperoxidation in caiman exposed to END (10, 100, 1000⯵g/egg), CYP (1, 10, 1000⯵g/egg), RU (500, 1000⯵g/egg) and PANZ (500, 1000⯵g/egg), DNA base oxidation in those exposed to END (10, 100, 1000⯵g/egg), CYP (1, 10⯵g/egg) and PANZ (500, 750⯵g/egg) as well as alteration in the activity of SOD in END 1⯵g/egg and CYP (10, 1000⯵g/egg). This study demonstrated the incidence of oxidative stress in animals exposed to pesticide formulations widely used in agricultural activity associated mainly with soybean crops, and add further information to that previously reported about pesticide effects in this native reptile species.
Assuntos
Jacarés e Crocodilos/metabolismo , Antioxidantes/metabolismo , Embrião não Mamífero/efeitos dos fármacos , Estresse Oxidativo , Praguicidas/toxicidade , Animais , Argentina , Ensaio Cometa , Casca de Ovo , Endossulfano/toxicidade , Eritrócitos/efeitos dos fármacos , Eritrócitos/enzimologia , Glicina/análogos & derivados , Glicina/toxicidade , Piretrinas/toxicidade , Substâncias Reativas com Ácido Tiobarbitúrico , GlifosatoRESUMO
Need for ecotoxicological information on local species has been recently highlighted as a priority issue in Latin America. In addition, little information has been found on concentration distances between lethal and sublethal effects, and the effect of mixtures at these two levels of analysis. Chlorpyrifos (CPF) is an organophosphate insecticide broadly used in soybean crops which has dramatically expanded in Latin America and other regions of the world. The aim of the present study was to evaluate lethal and sublethal effects of CPF, singly or in mixtures, on the inland "Pejerrey" (Odontesthes bonariensis) under laboratory conditions. Bioassays were performed using 15-30 d post hatch Pejerrey larvae. Six toxicity tests were run for estimating the average inter-assay dose-response curve of CPF and other six for assessing the effects of mixtures of CPF with endosulfan (EN) or lambda-cyhalothrin (LC), at three toxic units (TU) proportions (25:75, 50:50, 75:25). In addition, four assays were performed to describe the average inter-assay dose-response inhibition curve of acetylcholinesterase (AchE) for CPF alone and two for assessing the mixtures. The estimated 96 h-LC50 for CPF was 2.26 ± 1.11 µg/L and the incipiency value was 0.048 ± 0.012 µg/L, placing this Neotropical species among the 13% of worldwide fish more sensitive to CPF. In addition, the 96 h-LC50 for EN and LC were 0.30 ± 0.012 µg/L and 0.043 ± 0.031 µg/L, respectively. Therefore, relative toxicity of the three soybean insecticides for O. bonariensis was LC > EN > CPF. Effects of mixtures with EN and LC were variable, but in general fitted to both, independent action (IA) and concentration addition (CA) models. Slight antagonism was found when CPF TU proportions were above 50%. Therefore, from the regulatory point of view, the use of both mixture models, CA or IA, would be precautionary. Differential sensitivity to CPF was found for AchE inhibition at the head (96 h-IC50 = 0.065 ± 0.058 µg/L) and the body (96 h-IC50 = 0.48 ± 0.17 µg/L). In addition, whereas no significant effects induced by mixtures was observed in body AchE activity, antagonism was induced in head AchE inhibition in presence of both, EN and LC in the mixture. The lethal to sublethal ratio was close to 25.2 and 3.4 when comparing the CPF-LC50 and IC50s for head and body AchE activity, respectively. However, considerable overlapping was observed between concentration-response curves, indicating that the use of AchE as biomarker for environmental monitoring would be limited.
Assuntos
Clorpirifos/toxicidade , Endossulfano/toxicidade , Peixes/fisiologia , Inseticidas/toxicidade , Testes de Toxicidade , Animais , Inibidores da Colinesterase/toxicidade , Poluentes Químicos da Água/toxicidadeRESUMO
Endosulfan (ES) modifies the ultrastructure of skeletal muscle fibers and causes changes to the swimming behavior of fish. The objectives of the present work were to evaluate, in fishes of Australoheros facetus, 1) the integrity of myofibrils (Mf) by the analysis of SDS-PAGE profiles, and 2) the functionality of Mf through the microscopically monitoring of the contraction and changes in Mg2+ Ca2+- ATPase and Mg2+(EGTA) -ATPase activities. As expected, after the addition of the contraction buffer, control fish Mf contracted. On the contrary, Mf from fish exposed at 0.5⯵g/L ES showed a partial contraction and none of the fish exposed at 10⯵g/L ES contracted. As judged by its high Mg2+ Ca2+ ATPase activity and low Mg2+ (EGTA) ATPase activity, control Mf showed good functionality. In Mf from fish exposed to 0.5 and 10⯵g/L ES the activities of these enzymes were similar, suggesting denaturation or degradation of some component of tropomyosin-troponin complex. SDS-PAGE patterns of Mf from fish exposed to ES showed degradation of the myosin heavy chain and of tropomyosin. Similar values of lipid peroxidation (TBARS) were found in both control and exposed Mf, suggesting that lipid oxidation was not be related to the above-mentioned changes. The observed effects expand the knowledge of ES action in muscles and could be used as biomarkers of damage in fishes exposed to organochlorine compounds like the insecticide endosulfan.
Assuntos
Endossulfano/toxicidade , Biomarcadores Ambientais , Peixes/fisiologia , Hidrocarbonetos Clorados/toxicidade , Locomoção/efeitos dos fármacos , Músculos/efeitos dos fármacos , Praguicidas/toxicidade , Animais , Biomarcadores/metabolismo , Peixes/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Locomoção/fisiologia , Músculos/metabolismo , Músculos/fisiologia , Miofibrilas/efeitos dos fármacos , Miofibrilas/metabolismo , Cadeias Pesadas de Miosina/metabolismo , Tropomiosina/metabolismo , Troponina/metabolismoRESUMO
Our aim was to evaluate whether postnatal exposure to endosulfan (ENDO) modifies mammary gland (MG) development in pre- and post-pubertal male rats. From postnatal day 1 (PND1) to PND7, male rats were injected subcutaneously every 48h with either corn oil (vehicle) or 600µg ENDO/kg.bw. On PND21 and PND60, MG and blood samples were collected. Estradiol (E2) and testosterone (T) serum levels, MG histology, collagen fiber organization, proliferation index, and estrogen (ESR1) and androgen receptor (AR) expressions were evaluated. On PND21, E2 and T levels were similar between groups, whereas MG area, perimeter, number of terminal end buds and ESR1 expression were increased in ENDO-exposed rats. These changes were associated with alveolar development and increased organized collagen in the stroma. On PND60, a higher proliferation index in ENDO-exposed rats was correlated with a more developed lobuloalveolar structure. Hyperplastic alveoli and, hyperplastic ducts surrounded by a dense stroma were also observed in this group. T levels and ESR1 expression were similar between groups, whereas E2 levels and AR expression were decreased in ENDO-exposed rats. The exposure to ENDO in the first week of life interferes with the normal development of the MG and induces pre-malignant lesions in post-pubertal male rats.
Assuntos
Endossulfano/toxicidade , Glândulas Mamárias Animais/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Modelos Animais de Doenças , Endossulfano/sangue , Estradiol/sangue , Hiperplasia/sangue , Hiperplasia/induzido quimicamente , Masculino , Glândulas Mamárias Animais/crescimento & desenvolvimento , Ratos , Ratos Wistar , Receptores Androgênicos/genética , Receptores Androgênicos/metabolismo , Receptores de Estrogênio/genética , Receptores de Estrogênio/metabolismo , Testosterona/sangue , Receptor ERRalfa Relacionado ao EstrogênioRESUMO
We investigated the effects of the insecticide endosulfan on energy metabolism and its possible accumulation in fruit bats. Adult male bats (Artibeus lituratus) were exposed for 35 days, when they were offered fruit treated with endosulfan (E) and adhesive spreader (AS) in the following concentrations (g/L): 0.0; 0.0 (Control), 0.0; 0.015 (AS), 1.05; 0.015 (E1), 2.1; 0.015 (E2). Concentrations used were those recommended by the manufacturer for fruit crop application (E1) or twice this value (E2). E1 bats showed decreased plasma glucose concentration. Carcass fatty acids were decreased in E1 and E2 bats. Endosulfan bioaccumulation was observed in both liver and adipose tissues from E1 and E2 bats. These results indicate that the chronic exposure of fruit bats to environmentally relevant concentrations of endosulfan can lead to significant bioaccumulation beyond control and also decreased fatty acid content, which may impair the health of this important seed disperser in neotropical forests.
Assuntos
Quirópteros/metabolismo , Endossulfano/farmacocinética , Endossulfano/toxicidade , Ácidos Graxos/metabolismo , Tecido Adiposo/metabolismo , Animais , Glicemia/efeitos dos fármacos , Carga Corporal (Radioterapia) , Relação Dose-Resposta a Droga , Inseticidas/farmacocinética , Inseticidas/toxicidade , Fígado/metabolismo , MasculinoRESUMO
The organochlorine pesticide endosulfan (ES) is used in several countries as a wide spectrum insecticide on crops with high commercial value. Due to its high toxicity to non-target animals, its persistence in the environment and its ability to act as an endocrine disrupting compound in fish, ES use is currently banned or restricted in many other countries. Previous studies on the cichlid fish Cichlasoma dimerus have shown that waterborne exposure to ES can lead to both decreased pituitary FSH content and histological alterations of testes. As gonadotropin-stimulated sex steroids release from gonads was inhibited by ES in vitro, the aim of the present study was to elucidate possible mechanisms of disruption of ES on gonadal steroidogenesis in C. dimerus, as well as compare the action of the active ingredient (AI) with that of currently used commercial formulations (CF). Testis and ovary fragments were incubated with ES (AI or CF) and/or steroidogenesis activators or precursors. Testosterone and estradiol levels were measured in the incubation media. By itself, ES did not affect hormone levels. Co-incubation with LH and the adenylate cyclase activator forskolin caused a decrease of the stimulated sex steroids release. When co-incubated with precursors dehydroandrostenedione and 17αhydroxyprogesterone, ES did not affect the increase caused by their addition alone. No differences were observed between the AI and CFs, suggesting that the effect on steroidogenesis disruption is mainly caused by the AI. Results indicate that action of ES takes place downstream of LH-receptor activation and upstream of the studied steroidogenic enzymes.
Assuntos
Ciclídeos/metabolismo , Disruptores Endócrinos/toxicidade , Endossulfano/toxicidade , Estradiol/biossíntese , Ovário/efeitos dos fármacos , Testículo/efeitos dos fármacos , Testosterona/biossíntese , Poluentes Químicos da Água/toxicidade , Adenilil Ciclases/metabolismo , Animais , Colforsina/farmacologia , Ativação Enzimática , Ativadores de Enzimas/farmacologia , Feminino , Hormônio Luteinizante/farmacologia , Masculino , Ovário/enzimologia , Transdução de Sinais/efeitos dos fármacos , Testículo/enzimologia , Técnicas de Cultura de TecidosRESUMO
The combined effects of two widely used pesticides, endosulfan and cypermethrin, on survival of embryo-larval development of the South American toad (Rhinella arenarum) were examined. The toxicity bioassays were performed according to the AMPHITOX test. Embryos and larvae were exposed to mixtures of these pesticides at equitoxic ratios from acute or chronic exposure to evaluate interaction effects. The results were analyzed using both Marking's additive index and combination index (CI)-isobologram methods. Acute (96-h) and intermediate (168-h) toxicity of endosulfan-cypermethrin mixtures remained almost constant for larvae and embryos, but when exposure duration was increased, there was a significant elevation in toxicity, obtaining chronic (240-h) no-observed-effect concentrations (NOEC) values of 0.045 and 0.16 mg/L for embryos and larvae, respectively. These are environmentally relevant concentrations that reflect a realistic risk of this pesticide mixture to this native amphibian species. The toxicity increment with the exposure duration was coincident with the central nervous system development on embryos reaching the larval period, the main target organ of these pesticides. The interactions of the pesticide mixtures at acute and chronic exposure were antagonistic for embryo development (CI > 1), and additive (CI = 1) for larvae, while chronic exposure interactions were synergistic (CI < 1) for both developmental periods. Data indicated that endosulfan-cypermethrin mixtures resulted in different interaction types depending on duration and developmental stage exposed. As a general pattern and considering conditions of overall developmental period and chronic exposure, this pesticide mixture usually applied in Argentine crop fields is synergistic with respect to toxicity for this native amphibian species.
Assuntos
Bufo arenarum/metabolismo , Desenvolvimento Embrionário/efeitos dos fármacos , Endossulfano/toxicidade , Inseticidas/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bufo arenarum/crescimento & desenvolvimento , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimentoRESUMO
Studies regarding the effects of endocrine-disrupting chemicals (EDCs) on the reproductive functions of wild animals have raised increasing concern. Thus, here we evaluated the consequences of in ovo exposure to endosulfan (END) and bisphenol A (BPA) in testes from neonatal to juvenile (Juv) caimans (Caiman latirostris). Caiman eggs were collected from areas with low to moderate anthropogenic intervention and incubated at male-producing temperature. At stage 20 of embryonic development (previous to gonad sex determination), eggs were exposed to either END (20 ppm) or BPA (1.4 ppm) and male gonad histomorphology examined in 10-day-old, 90-day-old, and Juv caimans. The relative seminiferous tubular area (RTA) was measured in testes and the proliferation index and the expression of estrogen receptor alpha (ERα) were quantified in intratubular cells. Regardless of the treatment, all eggs resulted in male hatchlings. The testes of EDC-exposed caimans presented tortuous seminiferous tubules with empty tubular lumens. The RTA of 10-day-old caimans exposed to BPA was decreased. The percentage of cells expressing ERα was not different after in ovo treatment with EDCs (compared to the Control group), although caimans exposed to END showed a different ERα distribution pattern. The proliferation index was lower in 90-day-old caimans exposed to END, and higher in Juv caimans exposed to BPA. In ovo exposure to END or BPA modified sensitive parameters of C. latirostris male gonads. The alterations described here might compromise not only the sexual maturation but also the reproductive performance of adult caimans. J. Exp. Zool. 325A:84-96, 2016. © 2015 Wiley Periodicals, Inc.
Assuntos
Jacarés e Crocodilos/fisiologia , Disruptores Endócrinos/toxicidade , Reprodução/efeitos dos fármacos , Testículo/efeitos dos fármacos , Animais , Compostos Benzidrílicos/farmacologia , Compostos Benzidrílicos/toxicidade , Endossulfano/farmacologia , Endossulfano/toxicidade , Gônadas/efeitos dos fármacos , Masculino , Óvulo/efeitos dos fármacos , Óvulo/crescimento & desenvolvimento , Fenóis/farmacologia , Fenóis/toxicidade , Túbulos Seminíferos/efeitos dos fármacos , Túbulos Seminíferos/crescimento & desenvolvimentoRESUMO
El trauma ocular pediátrico es frecuente y es la principal causa de ceguera unilateral no congénita. La información en países en vías de desarrollo es escasa. El objetivo de esta serie de casos es describir las características clínicas y epidemiológicas del trauma ocular en niños menores de 14 años que consultaron al Hospital Dr. Rodolfo Robles Val verde en la Ciudad de Guatemala durante el año 2010. Se incluyeron 119 pacientes en el estudio. El género masculino en edad escolar (7-9 años) fue el más comprometido. El trauma más común fue el de globo cerrado. Los objetos más frecuentes causantes de la lesión fueron madera, juguetes y químicos. La vivienda fue el lugar donde más ocurrió el trauma. Se intervinieron 21 pacientes. Son necesarios programas de educación y prevención.
Pediatric ocular trauma is common and the leading cause of non congenital unilateral blindness. The information in developing countries is scarce. The objective of this case series is to describe clinical and epidemiological characteristics of ocular trauma in children under 14 years of age who visited Hospital Dr. Rodolfo Robles Valverde in Guatemala City in 2010. In this study 119 patients were included. School-aged (7-9 years) male gender was the most affected. Closed globe injury was the commonest. The most frequent objects causing the lesions were: wooden objects, toys and chemicals. Trauma occurred most frequently at home. Twenty one of the patients were surgically intervened. Education and prevention programs for pediatric ocular trauma are necessary.
Assuntos
Animais , Feminino , Masculino , Camundongos , Corpo Estriado/efeitos dos fármacos , Neurônios Dopaminérgicos/efeitos dos fármacos , Endossulfano/toxicidade , Inseticidas/toxicidade , Substância Negra/efeitos dos fármacos , Linhagem Celular Tumoral , Células Cultivadas , Sobrevivência Celular/efeitos dos fármacos , Corpo Estriado/metabolismo , Neurônios Dopaminérgicos/metabolismo , Intoxicação por MPTP , Neuroblastoma , Fatores Sexuais , Substância Negra/metabolismoRESUMO
Agroecosystems are usually polluted with a wide variety of contaminants with pesticides being very frequently detected. Endosulfan, an organochlorine pesticide, has been shown to cause both lethal and sublethal effects on aquatic organisms such as amphibians and especially on its early developmental stages. In this context, the aim of this study was to evaluate the uptake of environmentally relevant concentrations of endosulfan and its correlation with differential sensitivity in the early development stages of the common South American toad, Rhinella arenarum. Embryos and larvae were exposed to sublethal concentrations of endosulfan for several periods of exposures. According to the developmental stage at which they were exposed, the uptake rate was different. Bioconcentration factors (BCFs) for embryos significantly decreased with exposure time and concentration (p < 0.05) reaching a BCF of ≤1679 for embryos at 96 h of exposure to 0.001 mg endosulfan L(-1). BCFs for larvae significantly increased with exposure time (p < 0.05) obtaining a maximum of 40 at 504 h. In our previous study, we reported that embryos were less sensitive to the effects of endosulfan than larvae, which is in line with the main tendency of embryos to bioconcentrate endosulfan as observed in this study.
Assuntos
Endossulfano/toxicidade , Praguicidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Bufonidae , Testes de ToxicidadeRESUMO
Endosulfan (ES) is an organochlorine pesticide widely used in agriculture despite its high toxicity towards non-target organisms such as fish. It has been demonstrated that ES can cause negative effects on aquatic animals, including disruption of hormonal systems. However, the alterations produced by this pesticide on the reproductive axis of fish prior to sexual maturity, as well as possible modes of action have hardly been studied. This study aimed at assessing the effect of waterborne exposure to the pesticide ES on the reproductive axis during sexual differentiation of juveniles of the South American freshwater cichlid fish Cichlasoma dimerus. No mortality was observed due to ES subchronic exposure (90 days post-fertilization). Exposure to ES did not affect body weight nor morphometric parameters, indicating that larvae nutritional state was not affected. Timing of sexual differentiation, gonadal morphology and sex ratio were likewise not altered by ES. However, ES acted as an endocrine disrupting chemical in this species as the morphometry of gonadotropin-releasing hormones (GnRH) producing cells was altered. Exposure to ES altered nuclear area, cell area and nucleus/cytoplasm ratio of GnRH II neurons, and cell and nuclear area and diameter of GnRH III neurons. Interestingly, in our previous study, exposure before sex differentiation (30 day exposure) caused no alteration to GnRH II and III, and did alter GnRH I and FSH cells. These alterations could lead to changes in circulating hormone levels, especially when fish are exposed for prolonged periods, ultimately impairing reproductive fitness. C. dimerus juveniles can be an interesting biological model to perform toxicological studies with the intent to assess early disruption endpoints in the reproductive axis during development.
Assuntos
Ciclídeos/fisiologia , Endossulfano/toxicidade , Inseticidas/toxicidade , Neurônios/efeitos dos fármacos , Diferenciação Sexual/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Análise de Variância , Animais , Disruptores Endócrinos/toxicidade , Água Doce , Hormônio Liberador de Gonadotropina/metabolismo , Gônadas/efeitos dos fármacos , Hidrocarbonetos Clorados/toxicidade , Larva/efeitos dos fármacos , Precursores de Proteínas/metabolismoRESUMO
The objectives of this work were to evaluate the effects of environmentally relevant chlorpyrifos and endosulfan, concentrations in the incubation period, effective hatching and survival of embryos and neonates of the freshwater burrowing crab, Zilchiopsis collastinensis (Decapoda, Trichodactylidae). Both pesticides were prepared from commercial and technical grade products. The exposure to about 100, 200, and 400 ng endosulfan L(-1), and 48, 240, and 1,200 ng chlorpyrifos L(-1) did not cause differences in the incubation period or in effective hatching but decreased survival of neonates, especially in the concentrations prepared from the technical grade product. Even if these concentrations are below the median lethal concentration (LC50) values for embryos, these caused a significant decrease in the survival of neonates, i.e. when crabs are outside the egg and not protected by chorion. The decrease in the neonate population caused by these concentrations, which could be found in the environment, might impact aquatic communities.
Assuntos
Braquiúros/efeitos dos fármacos , Clorpirifos/toxicidade , Endossulfano/toxicidade , Inseticidas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Argentina , Braquiúros/embriologia , Relação Dose-Resposta a Droga , Embrião não Mamífero/efeitos dos fármacos , Larva/efeitos dos fármacos , Reprodução/efeitos dos fármacosRESUMO
We investigated whether neonatal exposure to low doses of endosulfan affects fertility and uterine functional differentiation at pre-implantation in rats. Newborn female rats received the vehicle, 0.2 µg/kg/d of diethylstilbestrol (DES), 6 µg/kg/d of endosulfan (Endo6) or 600 µg/kg/d of endosulfan (Endo600) on postnatal days (PND) 1, 3, 5, and 7. On PND90, the rats were mated to evaluate their reproductive performance on gestational day (GD) 19 and their ovarian steroid serum levels, endometrial proliferation and implantation-associated proteins on GD5. DES and endosulfan decreased the pregnancy rate and the number of implantation sites. On GD5, DES and endosulfan did not change the serum levels of 17ß-estradiol (E2) and progesterone (P); the endometrial proliferation decreased, which was associated with silencing of Hoxa10 in the Endo600-treated rats. Both doses of endosulfan increased the progesterone receptor (PR) expression, whereas the higher dose led additionally to an increase in estrogen receptor alpha (ERα). In the Endo600-treated rats, the down-regulation of Hoxa10 was associated with a deregulation of the steroid receptor coregulators. Alterations in endometrial proliferation and the endocrine pathway of Hoxa10/steroid receptors/coregulators might be the mechanism of endosulfan-induced implantation failure.
Assuntos
Implantação do Embrião/efeitos dos fármacos , Endossulfano/administração & dosagem , Fertilidade/efeitos dos fármacos , Inseticidas/administração & dosagem , Útero/efeitos dos fármacos , Animais , Animais Recém-Nascidos , Carcinógenos/administração & dosagem , Carcinógenos/toxicidade , Proliferação de Células/efeitos dos fármacos , Dietilestilbestrol/administração & dosagem , Dietilestilbestrol/toxicidade , Relação Dose-Resposta a Droga , Endossulfano/toxicidade , Feminino , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Inseticidas/toxicidade , Gravidez , Taxa de Gravidez , Ratos , Ratos Wistar , Esteroides/sangue , Útero/crescimento & desenvolvimentoRESUMO
Endosulfan is a widely used pesticide despite its extreme toxicity to a variety of taxa and its worldwide ban. The aim of the present study was to evaluate the acute and chronic toxicity of endosulfan on the embryonic-larval development of the common South American toad Rhinella arenarum. The results showed that lethal and sublethal effects increased with concentration and exposure time. The sensitivity to endosulfan increased during the larval period, the complete operculum stage (S.25) being the most sensitive (504-h median lethal concentration [LC50] = 0.01 mg endosulfan/L; 10% lethal concentration [LC10] = 0.004 mg endosulfan/L). Endosulfan exposure caused morphological abnormalities such as general underdevelopment, edema, gill malformations, and cellular dissociation as well as neurotoxicity. Our results also showed that larvae exposed to concentrations of 0.005 mg endosulfan/L and 0.01 mg endosulfan/L completed metamorphosis earlier than controls, but with underdevelopment. The 240-h teratogenic index was 6.13, implying a high risk for embryos to be malformed in the absence of significant embryonic lethality. Because the hazard quotients for chronic exposure were over 1, the level of concern value and toxicity endpoints obtained in the present study for R. arenarum occurred at concentrations lower than the levels of endosulfan reported in the environment, this pesticide should be considered a potential risk for this species.
Assuntos
Bufonidae/anormalidades , Embrião não Mamífero/efeitos dos fármacos , Endossulfano/toxicidade , Praguicidas/toxicidade , Teratogênicos/toxicidade , Animais , Embrião não Mamífero/anormalidades , Brânquias/anormalidades , Brânquias/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Metamorfose Biológica/efeitos dos fármacos , Microcefalia/induzido quimicamente , Medição de Risco , Cauda/anormalidades , Cauda/efeitos dos fármacosRESUMO
Previous studies in the wetland macrophyte Bidens laevis L have demonstrated that the insecticide endosulfan induces a high frequency of somatic chromosome aberrations in anaphase-telophase (CAAT) but no DNA changes as determined by the single cell gel electrophoresis (Comet) assay. Thus, cytogenetic biomarkers appear to be more sensitive to the toxic effects of the insecticide than the DNA molecule in the studied species. For this reason, the goals of this study were to use cytogenetic biomarkers--CAAT and abnormal metaphase--and defense biomarkers such as the activity of the antioxidant enzymes--guaiacol peroxidases (POD), glutathione reductase, and microsomal and cytosolic (m- and c-) glutathione-S-transferase (GST)--to evaluate in B. laevis effects caused by a commercial formulation of endosulfan. The frequency of CAAT was increased at 5, 10, 50, and 100 µg/L endosulfan with respect to the negative controls by 3.1, 2.5, 2.5, and 3.2-fold, respectively while the frequency of abnormal metaphases was also increased at the same concentrations by 3.5, 2.8, 3.2, and 11.3-fold, respectively. In addition to these aneugenic effects, other abnormalities such as C-mitosis and chromosome clumping were observed at 10 µg/L endosulfan. On the other hand, POD induction at 0.02, 0.5, 5, and 10 µg/L and m-GST inhibition at 0.5, 10, and 50 µg/L in plants exposed during 24 h to endosulfan were observed but all of these responses were highly variable. In conclusion, only cytogenetic biomarkers like CAAT in B. laevis can serve potentially as early warning systems to detect environmentally relevant concentrations of endosulfan in aquatic ecosystems.
Assuntos
Bidens/efeitos dos fármacos , Endossulfano/toxicidade , Inseticidas/toxicidade , Anáfase , Bidens/enzimologia , Bidens/genética , Biomarcadores/metabolismo , Aberrações Cromossômicas , Ensaio Cometa , Marcadores Genéticos , Glutationa Redutase/metabolismo , Glutationa Transferase/metabolismo , TelófaseRESUMO
Soybean pest control in Argentina is done just by chemical control using broad-spectrum pesticides. Alpaida veniliae (Araneae, Araneidae) is one of the most abundant spider species of the orb web weaver guild in soybean, and it is considered a very important polyphagous predator, attacking different insects' families. The objective of this study was to determine if neurotoxic insecticides commonly used in soybean crops and a new active ingredient registered in Argentina (spinosad) adversely affected survival, prey consumption, mating behaviour, web building and reproductive capacity of A. veniliae females, under standard laboratory conditions. Spinosad was the most harmful insecticide due to high acute toxicity, even at lower concentrations than those registered for its field use and for its sublethal effects also. Cypermethrin caused several sublethal effects although its acute toxicity on spider was lower than other insecticides. It reduced prey consumption, affected web building, caused abnormalities in eggs sacs and decreased drastically the fecundity and fertility at sublethal concentrations. Endosulfan did not reduce prey consumption but it affected web building, caused abnormalities in eggs sacs and egg masses, and decreased the fecundity and fertility. Spinosad was also the compound with the most drastic effect on web building, it did not reduce prey consumption and fecundity, but fertility was reduced and abnormalities in egg sacs and egg masses were observed. The use of these insecticides in IPM programs according to their potential toxicity on spider communities is discussed.
Assuntos
Inseticidas/toxicidade , Neurotoxinas/toxicidade , Aranhas/efeitos dos fármacos , Animais , Argentina , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Endossulfano/toxicidade , Feminino , Fertilidade/efeitos dos fármacos , Macrolídeos/toxicidade , Masculino , Óvulo/efeitos dos fármacos , Piretrinas/toxicidade , Comportamento Sexual Animal/efeitos dos fármacos , Aranhas/fisiologia , Fatores de TempoRESUMO
Global amphibian declines have many corroborative causes, and the use of pesticides in agriculture is a likely contributor. In places with high pesticide usage, such as Costa Rica, agrochemical pesticides may interact with other factors to contribute to rapid species losses. Classical ecotoxicological studies rarely address the effects of a pesticide in combination with other stressors. The present study investigated the synergistic roles of 2 pesticides (chlorothalonil and endosulfan), predator stress, and environmental regimes (controlled laboratory environments versus ambient conditions) on the survival of red-eyed tree frog larvae (Agalychnis callidryas). No synergistic effects of pesticide mixtures or predator stress were found on the toxicity of either chlorothalonil or endosulfan. Both pesticides, however, were considerably more toxic under realistic ambient temperature regimes than in a climate-controlled laboratory. Overall, endosulfan displayed the highest toxicity to tadpoles, although chlorothalonil was also highly toxic. The median lethal concentration estimated to kill 50% of a tested population (LC50) for endosulfan treatments under ambient temperatures was less than one-half of that for laboratory treatments (3.26 µg/L and 8.39 µg/L, respectively). Studies commonly performed in stable temperature-controlled laboratories may significantly underestimate toxicity compared with more realistic environmental regimes. Furthermore, global climatic changes are leading to warmer and more variable climates and may increase impacts of pesticides on amphibians.
Assuntos
Anuros/crescimento & desenvolvimento , Endossulfano/toxicidade , Exposição Ambiental/efeitos adversos , Nitrilas/toxicidade , Praguicidas/toxicidade , Animais , Biomassa , Costa Rica , Sinergismo Farmacológico , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Comportamento Predatório , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , TemperaturaRESUMO
Caiman latirostris is a reptilian species that exhibits temperature-dependent sex determination (TSD). Male-to-female sex reversal can be achieved after in ovo estrogen/xenoestrogen exposure. This is known as hormone-dependent sex determination (HSD). The amh, sox9 and sf-1 genes are involved in sex determination, sex differentiation, and steroidogenesis. The aims of this study were: (a) to establish the expression patterns of amh, sox9 and sf-1 mRNA in the gonad-adrenal-mesonephros (GAM) complexes of neonatal TSD-male and TSD-female caimans, (b) to compare the expression of these genes between TSD-females and HSD-females (born from E2-exposed eggs incubated at the male-producing temperature) and (c) to evaluate whether in ovo exposure to a low dose of E2 or bisphenol A (BPA) or to a high dose of endosulfan (END) modifies amh, sox9 or sf-1 mRNA expressions in neonatal males. The mRNA expressions of amh, sox9 and sf-1 in GAM complexes from TSD-males and TSD-females and from HSD-females were quantitatively compared by RT-PCR. A sexually dimorphic pattern of amh and sox9 mRNA expression was found, with a higher expression in TSD-males than in TSD-females. sf-1 mRNA did not differ between TSD-males and TSD-females. HSD-females exhibited a higher expression of sox9 than TSD-females. In males, increased mRNA expression of sex-determining genes was observed after in ovo exposure to END. E2 decreased sox9 but increased sf-1 mRNA expression. Changes induced by BPA were evident although not significant. These results provide new insights into the potential mechanisms that lead to the gonadal histo-functional alterations observed in caimans exposed to contaminated environments.