RESUMO
Pharmaceutical drugs are usually and continuously carried to the aquatic environment in different ways. Thus, they are pseudo-persistent in the environment, and they may exert deleterious effects on aquatic organisms. The objective of the present study was to investigate the acute and chronic effects of two widely used pharmaceutical drugs, paracetamol (analgesic and antipyretic) and propranolol (ß-blocker) on the activity of specific biomarkers (namely cholinesterase enzymes and lactate dehydrogenase) of the neotropical fish Phalloceros harpagos. The obtained results indicate an inhibition of the activity of the enzyme lactate dehydrogenase (LDH) after acute exposure to paracetamol, and an increase in cholinesterase activity in acutely propranolol-exposed fish. Chronic exposure to both drugs did not modify the enzymatic activities. Such short-term changes in enzymatic activities may be harmful to organisms, altering the preferential pathway of energy metabolism, and may induce behavioral changes that may compromise prey capture and predator escape, and in the longer term may induce population declines.
Assuntos
Acetaminofen/toxicidade , Colinesterases/metabolismo , Ciprinodontiformes/metabolismo , L-Lactato Desidrogenase/metabolismo , Propranolol/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Biomarcadores/metabolismo , Poluição Química da ÁguaRESUMO
In this work, the effect of supporting electrolytes on the simultaneous electrochemical oxidation of the pharmaceuticals sulfamethoxazole (SMX), propranolol (PRO), and carbamazepine (CBZ) in aqueous solutions has been studied. Based on the identified by-products, the degradation mechanisms were proposed and the acute toxicity was evaluated for each electrolyte. Assays were carried out in batch mode in a 2 L undivided reactor using a niobium coated with boron-doped diamond (Nb/BDD) mesh anode and Ti cathode at 2.5 A in presence of different supporting electrolytes (Na2SO4, NaCl, or NaBr) at the same concentration of 7 mM. The degradation rates were higher in the assays with NaCl and NaBr. Reaction by-products were identified by gas chromatography-mass spectrometry. Indirect oxidation by electrogenerated reactive halogen species (RHS) was the main mechanism when halide ions were used as electrolytes. Ten by-products were detected using Na2SO4 as electrolyte, while 19 (12 non-halogenated and 7 halogenated) and 20 (10 non-halogenated and 10 halogenated) using NaCl and NaBr respectively. The proposed degradation pathways involve transformation (hydroxylation, deamination, desulfonation, and halogenation) and bond rupture to produce less molecular weight compounds and their further transformation until total degradation. Chlorinated and brominated by-products confirm halogenation reactions. The electrogenerated RHS presented a significant inhibition effect on Vibrio fischeri; nevertheless, acute toxicity was not presented using Na2SO4 as electrolyte and a pharmaceutical concentration of 5 µg/L. In this view, the role of the supporting electrolyte in electrochemical oxidation process is crucial since it strongly influence degradation rate, by-products, and acute toxicity.
Assuntos
Carbamazepina/química , Eletrólitos/química , Propranolol/química , Sulfametoxazol/química , Poluentes Químicos da Água/química , Boro , Carbamazepina/toxicidade , Diamante , Eletrodos , Cromatografia Gasosa-Espectrometria de Massas , Oxirredução , Propranolol/toxicidade , Sulfametoxazol/toxicidade , Titânio , Testes de Toxicidade Aguda , Poluentes Químicos da Água/toxicidadeRESUMO
Pharmaceutical drugs in the aquatic environment can induce adverse effects on nontarget organisms. This study aimed to assess the short-term effects of sublethal concentrations of both paracetamol and propranolol on the fish Phalloceros harpagos, specifically light/dark preference, swimming patterns, skin pigmentation, histopathology, and liver glycogen levels. Fish were acutely exposed to sublethal concentrations of both paracetamol (0.008, 0.08, 0.8, 8, 80 mg L-1) and propranolol (0.0001, 0.001, 0.01, 0.1, 1 mg L-1) under controlled conditions. For scototaxis, a significant preference for the dark compartment was observed for the group exposed to the highest concentration of paracetamol (80 mg L-1). Propranolol exposure significantly altered the swimming pattern, especially in fish exposed to the 0.001 mg L-1 concentration. Pigmentation was reduced in propranolol-exposed fish (0.1, 1 mg L-1). The lowest concentration of propranolol (0.0001 mg L-1) induced a decrease of histochemical reaction for hepatic glycogen. These data demonstrate that pharmaceuticals can induce sublethal effects in nontarget organisms, even at low concentrations, compromising specific functions of the individual with ecological relevance, such as energy balance and behavior.
Assuntos
Acetaminofen/toxicidade , Ciprinodontiformes , Ecotoxicologia/métodos , Propranolol/toxicidade , Poluentes Químicos da Água/toxicidade , Acetaminofen/administração & dosagem , Animais , Comportamento Animal/efeitos dos fármacos , Relação Dose-Resposta a Droga , Biomarcadores Ambientais/efeitos dos fármacos , Feminino , Glicogênio/metabolismo , Fígado/metabolismo , Fígado/patologia , Masculino , Propranolol/administração & dosagem , Pigmentação da Pele/efeitos dos fármacos , Natação , Testes de Toxicidade Aguda , Poluentes Químicos da Água/administração & dosagemRESUMO
The occurrence of pharmaceuticals in the aquatic environment has received increasing attention in recent years, as concerns have risen about their environmental persistence, biological activity and different effects toward nontarget organisms. Considering the magnitude of concentrations (ng L(-1) to mg L(-1)) and their often-specific modes of action, the assessment of physiological responses of exposed aquatic biota may provide significant information regarding the potential ecological consequences of exposure to these contaminants. The present study intended to assess the acute and chronic effects of four pharmaceuticals: acetaminophen, chlorpromazine, diclofenac sodium and propranolol in the cladoceran species Daphnia magna. Parameters such as immobility, total of offspring and rate of population increase were analyzed. Results of acute exposures showed a considerable variability of toxicity among pharmaceuticals, with the following ranking of toxicity: diclofenac (EC50 = 123.3 mg L(-1)) < propranolol (EC50 = 5.531 mg L(-1)) < acetaminophen (EC50 = 2.831 mg L(-1)) < chlorpromazine (EC50 = 1.805 mg L(-1)). The chronic toxicity data showed the exertion of reproductive adverse effects. The compounds chlorpromazine and propranolol caused a significant decrease in fecundity, and the rate of population increase parameter suffered a significant decrease from 0.33 mg L(-1) to 0.128 mg L(-1) onwards, respectively. The levels of exposure to which our test organism was acutely and chronically exposed were above those already reported in the wild. Nevertheless, the extensive production, prescription and release of pharmaceuticals drugs will continue to grow in the future, and consequently their loadings to the environment can result in potential long-term ecological risks to aquatic biota.
Assuntos
Daphnia/efeitos dos fármacos , Reprodução/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Acetaminofen/administração & dosagem , Acetaminofen/toxicidade , Animais , Clorpromazina/administração & dosagem , Clorpromazina/toxicidade , Diclofenaco/administração & dosagem , Diclofenaco/toxicidade , Relação Dose-Resposta a Droga , Feminino , Propranolol/administração & dosagem , Propranolol/toxicidade , Ratos Wistar , Testes de Toxicidade Aguda , Testes de Toxicidade Crônica , Poluentes Químicos da Água/administração & dosagemRESUMO
Antihypertensive pharmaceuticals, including the beta-blockers, are one of the most detected therapeutic classes in the environment. The ecotoxicity of propranolol hydrochloride and losartan potassium was evaluated, both individually and combined in a binary mixture, by using the Lemna minor growth inhibition test. The endpoints evaluated in the single-pharmaceutical tests were frond number, total frond area and fresh weight. For the evaluation of the mixture toxicity, the selected endpoint was frond number. Water quality criteria values (WQC) were derived for the protection of freshwater and saltwater pelagic communities regarding the effects induced by propranolol and losartan using ecotoxicological data from the literature, including our data. The risks associated with both pharmaceutical effects on non-target organisms were quantified through the measured environmental concentration (MEC)/predicted-no-effect concentration (PNEC) ratios. For propranolol, the total frond area was the most sensitive endpoint (EC50 = 77.3 mg L(-1)), while for losartan there was no statistically significant difference between the endpoints. Losartan is only slightly more toxic than propranolol. Both concentration addition and independent action models overestimated the mixture toxicity of the pharmaceuticals at all the effect concentration levels evaluated. The joint action of both pharmaceuticals showed an antagonistic interaction to L. minor. Derived WQC assumed lower values for propranolol than for losartan. The MEC/PNEC ratios showed that propranolol may pose a risk for the most sensitive aquatic species, while acceptable risks posed by losartan were estimated for most of aquatic matrices. To the authors knowledge these are the first data about losartan toxicity for L. minor.
Assuntos
Araceae/efeitos dos fármacos , Losartan/toxicidade , Propranolol/toxicidade , Poluentes Químicos da Água/toxicidade , Anti-Hipertensivos/toxicidade , Ecotoxicologia/métodos , Monitoramento Ambiental/métodos , Medição de Risco/métodos , Qualidade da ÁguaRESUMO
The aim of our work was to study the hemodynamic effects of dynamic cardiomyoplasty on an acute animal model of atrial fibrillated heart failure. Eight anesthetized open chest dogs suffering from atrial fibrillation and heart failure, obtained by topic acetylcholine and propranolol, were treated by a cardiomyoplasty procedure performed with an electrostimulated latissimus dorsi muscle flap (LDMF). Values considered for analysis during LDMF stimulation were selected from cardiac cycles with R-R intervals similar to those when the LDMF was not stimulated (+/- 20 ms). Atrial fibrillated heart failure showed a significant increase of systemic vascular resistance, end diastolic left ventricular pressure (EDLVP) and right atrial pressure (p < 0.05), and a significant decrease in cardiac output, systolic left ventricular pressure (SLVP), and mean aortic pressure (p < 0.05) compared with control values. LDMF stimulation in atrial fibrillated heart failure resulted in a significant increase of SLVP, cardiac output, and mean aortic pressure (p < 0.05) and a significant decrease of systemic vascular resistance, EDLVP, and right atrial pressure (p < 0.05) compared with nonstimulated values. The highest LVP values were obtained with R-R intervals long enough to allow an adequate LV filling. We conclude that dynamic cardiomyoplasty provides an appropriate recovery in this animal model of atrial fibrillated heart failure. Cardiomyoplasty is an appropriate procedure for cardiac assist when R-R intervals allow an adequate LV filling.