RESUMO
The use of toxic pesticides has become a world problem because they can contaminate streams and rivers, producing an adverse impact on non-target aquatic biota, including fishes. Cypermethrin is one of the most important insecticides to control ectoparasites in wide-scale. The aim of this study was to evaluate the effect of commercial formulations of cypermethrin, SHERPA O (0.0, 0.075, 0.15, and 0.3 µg/L of cypermethrin) in fish Prochilodus lineatus for 96 h in semi-static condition, using biomarkers of genotoxicity: micronucleus frequency (MNF) in erythrocytes and biomarkers of oxidative damage: lipid peroxidation (TBARS) and antioxidant defenses, catalase (CAT) and glutathione (GSH) in liver tissue. Our results showed a significant decrease (p < 0.05) of CAT at pesticide concentrations of 0.150 and 0.300 µg/L, but no significant difference was observed in TBARS or GSH in any exposed group (p > 0.05) in comparison to the control. A significant increase was observed in the MNF in the group exposed to 0.3 µg/L of cypermethrin compared to negative control (p < 0.05). Finally, P. lineatus proved to be a sensitive species to the commercial formulations of cypermethrin and that CAT and MNF are effective indicators of these toxic effects.
Assuntos
Inseticidas/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Piretrinas/toxicidade , Animais , Antioxidantes/metabolismo , Catalase/metabolismo , Caraciformes , Relação Dose-Resposta a Droga , Eritrócitos/efeitos dos fármacos , Eritrócitos/metabolismo , Glutationa/metabolismo , Inseticidas/administração & dosagem , Testes para Micronúcleos , Piretrinas/administração & dosagemRESUMO
Prochilodus lineatus, a fish, was exposed to sublethal concentrations of cypermethrin: 0.075, 0.150, and 0.300 µg L(-1) and a control group (without cypermethrin) for 96 h. Five specimens were exposed in each concentration for triplicate (n = 60). Hepatic biochemical values and behavioral changes were studied. The results revealed a significantly higher level of aspartate aminotransferase, alanine aminotransferase, and alkaline phosphatase in hepatic tissue at different concentrations of cypermethrin tested compared to control (p < 0.05). A decrease in total protein was observed in exposed groups but not significantly (p > 0.05). This study provides information to know toxic mechanisms of cypermethrin on hepatic enzymes of P. lineatus that are poorly understood.
Assuntos
Inseticidas/toxicidade , Fígado/enzimologia , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Alanina Transaminase/metabolismo , Fosfatase Alcalina/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Caraciformes , Fígado/efeitos dos fármacosRESUMO
Some South American freshwater fishes can improve their capability of aquatic surface respiration (ASR) by developing dermal lip protuberances in the lower jaw. This adaptation was thought to be limited to omnivorous or herbivorous fishes. The present work provides the first evidence that juveniles of a piscivorous characid, Salminus brasiliensis, develop dermal lip protuberances during periods of hypoxia in floodplain ponds of the Salado River, in Argentina. The protuberance of S. brasiliensis involves dermal portions of both jaws exhibiting lateral lobes on the sides of the mouth arranged in the vertical plane. Water dissolved oxygen concentrations less than or equal to 1.05 mgl-1 were associated with a remarkable increase in lip protuberance. The lateral lobes of the protuberance in this species may limit the access of water to the anterior portion of the mouth which is positioned nearer to the oxygenated surface water during ASR. Finally, ASR, complemented with the development of dermal lip protuberances, can be considered a valuable strategy to survive in hypoxic environments, even for carnivorous fishes with elevated oxygen requirements.(AU)
Alguns peixes de água doce da América do Sul podem melhorar o desempenho da respiração aquática superficial (RAS) desenvolvendo protuberâncias dérmicas labiais na mandíbula. Considerava-se que essa adaptação era limitada aos peixes onívoros ou herbívoros. Este trabalho apresenta os primeiros indícios de que juvenis de um caracídeo piscívoro, Salminus brasiliensis, desenvolvem protuberâncias dérmicas labiais durante períodos de hipoxia em lagoas de várzea do rio Salado, Argentina. As protuberâncias de S. brasiliensis envolvem porções dérmicas das duas mandíbulas e exibem lóbulos laterais ao lado da boca dispostas no plano vertical. Concentrações de oxigênio dissolvido na água, inferiores ou iguais a 1,05 mgl-1, foram associadas a um aumento notável no desenvolvimento das protuberâncias labiais. Nesta espécie os lóbulos laterais da protuberância podem limitar o acesso de água à porção anterior da boca, que está posicionada mais perto da superfície da água oxigenada durante a RAS. Finalmente, a RAS, complementada com o desenvolvimento de protuberâncias dérmicas labiais, pode ser considerada uma valiosa estratégia para a sobrevivência em ambientes hipóxicos, mesmo para peixes carnívoros com elevada demanda de oxigênio.(AU)
Assuntos
Animais , Characidae/anatomia & histologia , Characidae/anormalidades , HipóxiaRESUMO
Some South American freshwater fishes can improve their capability of aquatic surface respiration (ASR) by developing dermal lip protuberances in the lower jaw. This adaptation was thought to be limited to omnivorous or herbivorous fishes. The present work provides the first evidence that juveniles of a piscivorous characid, Salminus brasiliensis, develop dermal lip protuberances during periods of hypoxia in floodplain ponds of the Salado River, in Argentina. The protuberance of S. brasiliensis involves dermal portions of both jaws exhibiting lateral lobes on the sides of the mouth arranged in the vertical plane. Water dissolved oxygen concentrations less than or equal to 1.05 mgl-1 were associated with a remarkable increase in lip protuberance. The lateral lobes of the protuberance in this species may limit the access of water to the anterior portion of the mouth which is positioned nearer to the oxygenated surface water during ASR. Finally, ASR, complemented with the development of dermal lip protuberances, can be considered a valuable strategy to survive in hypoxic environments, even for carnivorous fishes with elevated oxygen requirements.(AU)
Alguns peixes de água doce da América do Sul podem melhorar o desempenho da respiração aquática superficial (RAS) desenvolvendo protuberâncias dérmicas labiais na mandíbula. Considerava-se que essa adaptação era limitada aos peixes onívoros ou herbívoros. Este trabalho apresenta os primeiros indícios de que juvenis de um caracídeo piscívoro, Salminus brasiliensis, desenvolvem protuberâncias dérmicas labiais durante períodos de hipoxia em lagoas de várzea do rio Salado, Argentina. As protuberâncias de S. brasiliensis envolvem porções dérmicas das duas mandíbulas e exibem lóbulos laterais ao lado da boca dispostas no plano vertical. Concentrações de oxigênio dissolvido na água, inferiores ou iguais a 1,05 mgl-1, foram associadas a um aumento notável no desenvolvimento das protuberâncias labiais. Nesta espécie os lóbulos laterais da protuberância podem limitar o acesso de água à porção anterior da boca, que está posicionada mais perto da superfície da água oxigenada durante a RAS. Finalmente, a RAS, complementada com o desenvolvimento de protuberâncias dérmicas labiais, pode ser considerada uma valiosa estratégia para a sobrevivência em ambientes hipóxicos, mesmo para peixes carnívoros com elevada demanda de oxigênio.(AU)
Assuntos
Animais , Characidae/anatomia & histologia , Characidae/anormalidades , HipóxiaRESUMO
Toxicants on fish may induce genetic alterations that can be used as genotoxic markers. We evaluated DNA damage using alkaline comet assay applied on erythrocytes after in vivo exposure of Prochilodus lineatus to different concentrations of Cypermethrin (0.300, 0.150, 0.075 and 0.000 microg/L) as a probable chemical mutagen. The results revealed a significantly higher level of DNA damage at all concentrations of Cypermethrin tested compared to control and background level (p < 0.05). We have standardized the technique for one of the most common native fish species that will be useful for biomonitoring genotoxicity in polluted waters of the region.
Assuntos
Ensaio Cometa/métodos , Peixes/genética , Inseticidas/toxicidade , Piretrinas/toxicidade , Poluentes Químicos da Água/toxicidade , Álcalis , Animais , Dano ao DNA , Monitoramento AmbientalRESUMO
Freshwater fish Prochilodus lineatus were exposed to sublethal concentrations of cypermethrin (0.3 and 0.6 microg/l) for 2, 5 and 8 days. It was observed that with the increase of exposure time total erythrocyte (RBC), hemoglobin (Hb), hematocrit (Ht) and mean corpuscular hemoglobin concentration (MCHC) values decreased but mean corpuscular volume (MCV) and mean corpuscular hemoglobin (MCH) values increased. These reports indicate that hematological parameters, may be useful as a diagnostic test for cypermethrin exposure in aquatic organisms.
Assuntos
Peixes/sangue , Inseticidas/toxicidade , Piretrinas/toxicidade , Animais , Contagem de Eritrócitos , Índices de Eritrócitos , Hematócrito , Hemoglobinas/análise , Poluentes Químicos da Água/toxicidadeRESUMO
The purpose of this study was to investigate if specific immune responses were present in mice bearing a lung adenocarcinoma that presents paraneoplastic syndromes during tumor evolution. Leukocytosis, mainly due to polymorphonuclear leukocytes, was found from day 15 of tumor growth. Delayed type hypersensitivity response and increased interleukin-6 (IL-6) serum levels were observed along tumor growth. Concomitant immunity, specific rejection of a second inoculum and in vitro specific cytotoxicity occurred at 20 days of implant. In advanced stages of tumor evolution impaired cytotoxicity, accompanied by a great increase of IL-6 in serum, were observed. Role of polymorphonuclear leukocytes and IL-6 overproduction as responsible for immune dysregulation and paraneoplastic syndromes are discussed.
Assuntos
Adenocarcinoma/imunologia , Neoplasias Pulmonares/imunologia , Síndromes Paraneoplásicas/imunologia , Adenocarcinoma/sangue , Animais , Divisão Celular , Hipersensibilidade Tardia/imunologia , Imunidade Celular , Imunização , Interleucina-6/sangue , Contagem de Leucócitos , Neoplasias Pulmonares/sangue , Linfócitos/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Transplante de Neoplasias , Síndromes Paraneoplásicas/sangue , Baço/patologia , Células Tumorais CultivadasRESUMO
Paraneoplastic syndromes are rarely described in animal models. It may be useful to have a suitable experimental model to study the mechanisms by which they are produced. In this study, we describe a murine lung adenocarcinoma, P07, which presents hypercalcemia, leukocytosis and cachexia. We determined the presence of PTHrP in plasma as well as GM-CSF produced by P07 cells. TNF-alpha, which is responsible for cachexia, could neither be detected in serum nor in P07 cell supernatants. We conclude that this model, which shows paraneoplastic syndromes similar to those of lung tumor patients, should be useful to study the pathways and significance of these signs.
Assuntos
Adenocarcinoma/fisiopatologia , Neoplasias Pulmonares/fisiopatologia , Síndromes Paraneoplásicas/fisiopatologia , Adenocarcinoma/sangue , Adenocarcinoma/patologia , Alanina Transaminase/sangue , Fosfatase Alcalina/sangue , Animais , Aspartato Aminotransferases/sangue , Proteínas Sanguíneas/análise , Caquexia/fisiopatologia , Cálcio/sangue , Feminino , Fator Estimulador de Colônias de Granulócitos e Macrófagos/biossíntese , Hematócrito , Contagem de Leucócitos , Neoplasias Pulmonares/sangue , Neoplasias Pulmonares/patologia , Camundongos , Camundongos Endogâmicos BALB C , Síndromes Paraneoplásicas/sangue , Proteína Relacionada ao Hormônio Paratireóideo , Proteínas/análise , Células Tumorais CultivadasRESUMO
Ovariectomy and immobilization in rats have demonstrated to be useful models for osteopenia and they are considered to mimic some aspects of human osteoporosis associated with a deficit of ovarian hormones and the absence of mechanical function (disuse of the bone). Pamidronate (APD) and Olpadronate (OLPA), a new dimethylated aminobisphosphonate, on a continuous oral scheme (APD: 8 and OLPA: 0.8 mg/kg/day) or on an intermittent parenteral scheme (APD: 1.25 and OLPA: 0.075 mg/kg every 15 days) did effectively prevent the trabecular bone loss caused by immobilization (unilateral sciaticectomy), by lack of ovarian stimuli (bilateral ovariectomy) or by both approaches. There were no signs of deterioration in the cortical bone mass. In a model of preestablished osteopenia, caused by estrogen deprivation, OLPA stopped the progression of the bone mass loss (0.5 mg/kg/i.v. every 15 days) and restored (0.30-0.60 mg/kg/i.v. every 15 days) the bone mineral density which had been affected (trabecular and cortical). The different activity of OLPA and APD on trabecular and cortical regions of long bones seems to accompany their different responses because of negative stimulus: better responses were more evident in the trabecular bone which proved to be more labile. In these "in vivo" models of OLPA's efficacy was similar to APD's but it was roughly 5-10 times more potent. OLPA has a high safety margin. Therefore, it could advantageously be used in those bone diseases which benefit with the use of bisphosphonates.
Assuntos
Densidade Óssea/efeitos dos fármacos , Doenças Ósseas Metabólicas/tratamento farmacológico , Osso e Ossos/efeitos dos fármacos , Difosfonatos/farmacologia , Análise de Variância , Animais , Doenças Ósseas Metabólicas/metabolismo , Osso e Ossos/metabolismo , Difosfonatos/metabolismo , Feminino , Masculino , Ovariectomia , Pamidronato , Ratos , Ratos WistarRESUMO
Bisphosphonates regulate bone turnover by inhibiting osteoclastic bone resorption. Due to their pharmacodynamic and pharmacokinetic characteristics, bisphosphonates have a special pharmacotoxicological profile related to their high degree of specificity: low or non-existent distribution in soft tissues and strong affinity for calcified tissues. Some general conclusions may be drawn from the pre-clinical toxicological studies, whose main aim is to identify the toxicity target organ/s and estimate the safety margins of a "prospective therapeutic agent" in laboratory animals. They are based on our own results and on data from the available literature as regards various bisphosphonates: Alendronate, Clodronate, Etidronate, Olpadronate and Pamidronate. Generally, very high doses of bisphosphonates are required to produce in different levels and incidence various extra-skeletical toxic side effects: local reaction, hypocalcemia (and its consequences on the cardiovascular system and the possibility of tetany), affection of the dental structures and renal dysfunction. Most of side effects may be related to the low solubility in biological fluids, the formation of calcium complexes, the potent inhibitory effect of endogenous or induced bone resorption as well as to its main excretion pathway. Some other side effects (on the eye, lungs and liver), may be related to repeated excessive high doses. A safety margin of 200 to 300 : 1 between the "toxic" and "pharmacological" doses may be estimated if the total quantity of Olpadronate given to various animal species in toxicological studies and in pharmacodynamic experimental models (osteopenias due to estrogen deprivation or immobilization and retinoid-induced hypercalcemia) is considered. If the toxic doses in animals are related to the highest doses suggested for human beings, then the ratio increases from 300 to 1000 : 1 depending on the pathology and the route of administration. As regards their effect on the bone, experimental data with the new bisphosphonates suggest a significant dissociation between pharmacologically active doses and those ones producing defective mineralization. The excessive inhibition of bone remodelling, due to the use of high doses in normal animals, is the natural consequence of the pharmacological effect of this family of compounds. A bisphosphonate's toxic potential effect on bone should not be evaluated in normal animals but in particular situations with a high bone turnover. Furthermore, the doses should be adjusted in order to regulate the magnitude of bone remodelling inhibition so as to take it to a normal level without totally suppressing it. Potency, safety margins, doses and proper administration schemes, should be considered as key elements for the optimum use of the therapeutic potentiality of these compounds.