Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.963
Filtrar
1.
Bull Entomol Res ; 110(1): 106-114, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31190655

RESUMO

We investigated the effects of the antiparasitic drug ivermectin on the dung beetles Copris acutidens Motschulsky, Onthophagus bivertex Heyden, O. lenzii Harold and Phelotrupes auratus auratus Motschulsky in Japan. Ivermectin was detected in cattle dung from 1 to 3 or 7 days post-treatment, with a peak at 3 days post-treatment in two pour-on administrations (500 µg kg-1). In C. acutidens, adult survivals and numbers of brood balls were significantly reduced in dung collected at 3 and 7 days post-treatment, and adult emergence rates were significantly decreased in dung collected at 7 and 14 days post-treatment. Feeding activity of C. acutidens was inhibited in dung collected at 3 days post-treatment, but was not significantly different from that seen in control dung at 7 and 14 days post-treatment. In O. bivertex and O. lenzii, there were no effects of ivermectin on adult survival or feeding activities, but the numbers of brood balls of O. bivertex constructed in dung collected at 3 and 7 days post-treatment were significantly lower than observed with control dung. The adult emergence rates of O. bivertex and O. lenzii were significantly reduced in dung collected at 1 to 3 and 1 to 7 days post-treatment, respectively. In P. auratus, there were no effects of ivermectin on adult survival, oviposition, feeding activity, or larval survival (until the third instar) in dung at 3 days post-treatment. The environmental risks affecting the populations of dung beetles in Japan are discussed.


Assuntos
Antiparasitários/toxicidade , Besouros/efeitos dos fármacos , Ivermectina/toxicidade , Animais , Antiparasitários/análise , Fezes/química , Comportamento Alimentar/efeitos dos fármacos , Feminino , Ivermectina/análise , Masculino , Reprodução/efeitos dos fármacos , Testes de Toxicidade Subcrônica
2.
J Agric Food Chem ; 68(1): 88-96, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31826619

RESUMO

Solanum rostratum is a worldwide malignant invasive weed, causing serious harm to the ecological environment and biodiversity. Strong chemical defense against herbivorous insects is supposed to be one of the successful invasive mechanisms of this exotic plant. However, the real defense components and their action mechanisms and distributions are still unknown. To address these problems, we bioassay-guided isolated compounds from the aerial part of S. rostratum and determined their structures using high-resolution electrospray ionization mass spectrometry, nuclear magnetic resonance, and electronic circular dichroism calculation. One new and seven known compounds were identified, and all of the isolates exhibited different levels of antifeedant activities, especially compounds 1 and 4. Consistently, compounds 1 and 4 displayed potent inhibitory effects on antifeedant-related enzymes (AchE and CarE). The action mechanisms of active compounds 1 and 4 were revealed by molecular docking and molecular dynamic simulation studies. Furthermore, the distributions of the active compounds in leaves, stems, and flowers were also analyzed by liquid chromatography-mass spectrometry.


Assuntos
Comportamento Alimentar/efeitos dos fármacos , Inseticidas/farmacologia , Mariposas/efeitos dos fármacos , Extratos Vegetais/farmacologia , Plantas Daninhas/química , Solanum/química , Animais , Flores/química , Flores/metabolismo , Inseticidas/química , Inseticidas/isolamento & purificação , Inseticidas/metabolismo , Simulação de Acoplamento Molecular , Estrutura Molecular , Mariposas/fisiologia , Extratos Vegetais/química , Extratos Vegetais/isolamento & purificação , Extratos Vegetais/metabolismo , Folhas de Planta/química , Folhas de Planta/metabolismo , Plantas Daninhas/metabolismo , Metabolismo Secundário , Solanum/metabolismo , Espectrometria de Massas por Ionização por Electrospray
3.
Chemosphere ; 238: 124609, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31524604

RESUMO

Human pharmaceuticals are pollutants of special concern due to their widespread consumption over the last decades, their high persistence in the environment, and the reported alterations produced on non-target organism. The antidepressant fluoxetine (FLX) exerts its effect by inhibiting serotonin (5-HT) reuptake at the presynaptic membrane, thus increasing brain serotonergic activity. In vertebrates, there is a clear inverse relationship between hypothalamic 5-HT levels and food intake, therefore we hypothesized that FLX would inhibit food intake, and in consequence alter energy metabolism in freshwater fish. The aim of this study was to analyze the effect of FLX on feeding behavior and energy storage of the cichlid fish Cichlasoma dimerus. Adult fish were intraperitoneally injected daily with 2 or 20 µg.g-1 FLX or saline for a 5-day period, during which the 20 µg.g-1 FLX-injected fish exhibited a marked reduction in food intake, consistent with a decrease in total body weight and total hepatocyte area observed at the end of the experiment. Although not statistically significant, a marked 50% decrease in glycogen and lipid content and an increase in protein levels in liver was observed for the 20 µg.g-1 FLX dose. This was evidenced histochemically by a weak PAS positive reaction and an intense Coomasie Blue stain. Taken together, these results suggest that the SSRI antidepressant FLX produces an anorectic effect in adults of C. dimerus, which could alter normal physiological function and, in consequence, have a negative impact on fish growth, reproduction, and population success.


Assuntos
Ciclídeos/metabolismo , Metabolismo Energético/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Fluoxetina/toxicidade , Inibidores de Captação de Serotonina/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Hipotálamo/efeitos dos fármacos , Fígado/metabolismo , Masculino , Reprodução/efeitos dos fármacos
4.
J Insect Sci ; 19(5)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31616937

RESUMO

We evaluated the insecticide activities of aqueous extracts of five species of plants from the Ecuadorian Amazon (Deguelia utilis (ACSm.) AMGAZEVEDO (Leguminosae: Papilionoideae), Xanthosoma purpuratum K. Krause (Alismatales: Araceae), Clibadium sp. (Asteracea: Asterales), Witheringia solanacea L'Hér (Solanales: Solanaceae), and Dieffenbachia costata H. Karst. ex Schott (Alismatales: Araceae)) plus Cymbopogon citratus Stapf. (Poales: Poaceae) under laboratory, open-field conditions in Plutella xylostella L. (diamondback moth), and semifield conditions in Brevicoryne brassicae L. Tap water was used as a negative control, and synthetic insecticides were used as positive controls. In a laboratory bioassay, aqueous extracts of D. utilis resulted in P. xylostella larval mortality. In contrast to chlorpyrifos, all botanicals were oviposition deterrents. All extracts except Clibadium sp. decreased leaf consumption by P. xylostella larvae. In semifield experiments, D. utilis, Clibadium sp., D. costata, and X. purpuratum initially controlled the population of B. brassicae, but 7 d after application, all botanicals except the D. utilis lost their ability to control the pest. In field experiments on broccoli crops in both dry and rainy seasons, the extracts did not control the abundance of P. xylostella, where as a mixture of two insecticides (chlorpyrifos + lambda cyhalothrin) did. These results show some incongruences from laboratory to semifield and field conditions, indicating that more studies, including the identification of the chemicals responsible for the biological activity, its stability, and the effects of chemotypes on insecticidal activity, are needed to understand the potential of these plant species as botanical insecticides.


Assuntos
Afídeos , Controle de Insetos , Inseticidas , Mariposas , Extratos Vegetais , Animais , Afídeos/crescimento & desenvolvimento , Equador , Comportamento Alimentar/efeitos dos fármacos , Feminino , Larva/crescimento & desenvolvimento , Mariposas/crescimento & desenvolvimento , Ninfa/crescimento & desenvolvimento , Oviposição/efeitos dos fármacos
5.
J Insect Sci ; 19(5)2019 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-31665784

RESUMO

Insect herbivores can modify their foraging behavior to obtain a balanced food intake, and they tend to move between food sources with different nutrient values. We investigated this movement in early instar larvae of Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae) using a putative optimal artificial diet (OP) and high protein (HP) and high carbohydrate (HC) artificial diets based on protein (p) and carbohydrate (c) ratios. Larvae were allowed to choose between the same kind of diet cubes (effectively no-choice), or diet cubes with different p: c ratios. In no-choice tests, we found that first instar larvae remained longest on OP diet and spent the least time on HC diet, while third instar larvae remained longest on HC diet and spent least time on OP diet. First instar larvae moved the most when provided with HC diet, while third instar larvae moved most when provided with OP diet. However, both stages moved the least when allowed to choose between diet cubes with different p: c ratios. The relative growth rate decreased when larvae increased their movement, but this influence was not evident when larvae fed on HC diet. Larvae that fed only on HC diet had the highest relative growth rate, followed by larvae with access to all diets simultaneously, indicating a behavior to mix nutrient intake. We relate these findings to behavior of this major pest species under field conditions.


Assuntos
Ração Animal/análise , Carboidratos da Dieta/análise , Proteínas na Dieta/análise , Mariposas/efeitos dos fármacos , Animais , Dieta , Comportamento Alimentar/efeitos dos fármacos , Larva/efeitos dos fármacos , Larva/crescimento & desenvolvimento , Larva/fisiologia , Mariposas/crescimento & desenvolvimento , Mariposas/fisiologia , Movimento/efeitos dos fármacos
6.
Mar Pollut Bull ; 145: 23-27, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31590781

RESUMO

Pollution by microplastics has become a global threat affecting coastal habitats such as sandy beaches and their resident macrofauna. The goal of this study was to assess the influence of microplastics on the feeding behavior and growth rate of a widespread sandy beach amphipod, Orchestoidea tuberculata. These organisms were exposed to artificial food prepared with Poly(styrene-co-divinylbenzene) microspheres (8 µm particle size) at 3 different concentrations (0%, 5% and 10%). The amphipods consumed significantly more food when the concentration of microplastics was 0% and significantly less when the concentration was 10%, both in trials in which they had a choice (preference experiments) and those in which they did not have a food choice. In contrast to this, the amphipod's absorption efficiency and estimated growth rates were not significantly affected by the concentration of microplastics. Combined, these results indicate that high microplastics concentrations (e.g. 10%) cause a reduction in the amphipod's consumption rates and, indirectly, may affect the role of this species as a main consumer of stranded seaweeds in sandy beaches ecosystems.


Assuntos
Anfípodes/efeitos dos fármacos , Anfípodes/fisiologia , Plásticos/farmacologia , Animais , Ecossistema , Poluição Ambiental , Comportamento Alimentar/efeitos dos fármacos , Plásticos/análise , Alga Marinha
7.
Environ Pollut ; 255(Pt 1): 113181, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31522006

RESUMO

Extensive application of fullerene nanoparticles (nC60) leads to potential environmental pollution. The acute toxic effects of nC60 have been largely investigated, but studies of behavioural and chronic toxicity at sublethal doses are still rare and the underlying molecular mechanisms remain unknown. The present study investigated behavioural and chronic toxicity of nC60 to Daphnia magna. The results showed that, in response to nC60 exposure, hopping, heartbeat frequencies and feeding ability of D. magna decreased significantly, displaying negative relationship with exposure time and dose. Chronic treatments with 0.1 mg/L or 1 mg/L nC60 for 21 days significantly reduced survival and reproduction of D. magna. These harmful effects suggested negative impacts of nC60 on aquatic ecosystems. Moreover, transcriptome analysis showed that the behavioural and chronic toxicity of nC60 to D. magna might be related to physiological functions such as cell structural repair, protein degradation, energy metabolism and reproduction. We found that nC60 accumulated in guts of D. magna, which should be responsible for the decrease of food ingestion and consequently inhibiting energy intake. Deficiency of energy not only affects behaviours but also declines reproduction in D. magna. Overall, this is the first study comprehensively considered the behavioral and chronic toxicity of nC60 to aquatic organism. The results should be helpful to better understand the ecological consequences of C60 released into water environments.


Assuntos
Daphnia/efeitos dos fármacos , Fulerenos/toxicidade , Nanopartículas/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Comportamento Animal/efeitos dos fármacos , Daphnia/genética , Daphnia/fisiologia , Ecossistema , Comportamento Alimentar/efeitos dos fármacos , Fulerenos/química , Perfilação da Expressão Gênica , Nanopartículas/química , Reprodução/efeitos dos fármacos
8.
J Dairy Sci ; 102(11): 9767-9780, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31495615

RESUMO

Our objective was to determine the effects of uncouplers of oxidative phosphorylation on feeding behavior of lactating dairy cows. We hypothesized that uncouplers of oxidative phosphorylation would increase meal size and meal length and performed 2 experiments to test our hypothesis. In experiment 1, 4 late-lactation cows (345 ± 48.4 d in milk; mean ± SD) were administered a daily intrajugular injection of either 10 mg/kg of BW0.75 of 2,4-dinitrophenol methyl ether (DNPME) and propylene carbonate or propylene carbonate (control; CON) in a crossover design with 2-d periods. In experiment 2, 8 early-lactation cows (11.3 ± 0.89 d in milk) were administered a daily intrajugular injection via jugular catheter of either 50 mg/kg of BW of sodium salicylate (SAL) and saline or saline (control; CON) in a crossover design with 1-d periods. Feeding behavior was recorded by a computerized data acquisition system and analyzed for the first 4 h after access to feed within 15 min of treatment for both experiments. Neither DNPME nor SAL affected meal size over the first 4 h after access to feed. However, DNPME increased meal length by 6.4 min (26.3 vs. 19.9 min) and tended to decrease the number of meals (2.55 vs. 2.78 meals/4 h) over the first 4 h after access to feed compared with CON. Both DNPME and SAL decreased eating rate over the first 4 h after access to feed compared with their respective controls (0.10 vs. 0.12 kg/min for DNPME vs. CON; 0.06 vs. 0.07 kg/min for SAL vs. CON). Lack of treatment effects on meal size may have been caused by increased rate of oxidation of fuels compensating for the disruption of oxidative phosphorylation.


Assuntos
Bovinos/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Fosforilação Oxidativa/efeitos dos fármacos , Salicilato de Sódio/farmacologia , Desacopladores/farmacologia , Ração Animal/análise , Animais , Aleitamento Materno , Estudos Cross-Over , Dieta/veterinária , Feminino , Lactação/efeitos dos fármacos , Fígado/química , Leite , Salicilato de Sódio/administração & dosagem , Desacopladores/administração & dosagem
9.
Bull Environ Contam Toxicol ; 103(5): 663-669, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31473775

RESUMO

Climate change is expected to alter hydrological cycles on global and regional scales, impacting groundwater and surface water inputs to stream habitats. In the midwestern United States, the volume and frequency of inputs are expected to become increasingly variable. This region has a high incidence of agriculture, creating enormous potential for transport of pesticides and herbicides into aquatic ecosystems. Metolachlor, an herbicide for corn and soybean crops, has been demonstrated to contaminate surface water and groundwater in the region. This study examines the impact of variable flow conditions on the toxicity of environmentally relevant concentrations of metolachlor in a macroinvertebrate found in midwestern streams, the rusty crayfish (Faxonius rusticus). Changes in crayfish foraging behavior were analyzed using a Mixed Model ANCOVA. Under toxicant exposure, crayfish significantly increased their consumption of macrophytes, but only under the variable flow regime. Thus, the increased variability in toxicant exposure impacted crayfish foraging behavior more than other flow regimes. This significant interaction between flow regime and metolachlor exposure suggests that the greater variability in toxicant inputs to streams may lead to more severe changes in behavior for exposed organisms.


Assuntos
Acetamidas/toxicidade , Astacoidea/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos , Herbicidas/toxicidade , Ciclo Hidrológico , Poluentes Químicos da Água/toxicidade , Animais , Astacoidea/fisiologia , Ecossistema , Água Subterrânea/química , Meio-Oeste dos Estados Unidos , Rios/química
10.
Aquat Toxicol ; 215: 105266, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31401474

RESUMO

The persistent pollutants polybrominated diphenyl ethers (PBDEs) have been demonstrated to produce several negative effects on marine organisms. Although Mytilus galloprovincialis was extensively studied as model system, the effects of PBDEs on the innate immune system of mussels remains unclear. In this study, except for the control treatment, specimens of M. galloprovincialis were fed with microalgae treated with increasing concentrations of PBDEs (maximum level 100 ng L-1 of BDE-47 per day). BDE-47 treatment was maintained for 15 days and then the animals were fed with the same control diet, without contaminants, for 15 days. Samples of haemolymph (HL) were obtained at T0, T15 and T30 days of the experiment to evaluate different parameters related to immunity, such as neutral red retention time, and peroxidase, protease, antiprotease, lysozyme and bactericidal activities. BDE-47 exposure for 15 days affected both the stability of haemocytes and humoral parameters. In addition, the obtained results indicated that, at 30 days, after 15 days of culture without contaminant, the immune parameters were still affected, as some of them did not return to the basal levels, and others remained stimulated. Overall the results indicate that BDE-47 exposures at environmentally realistic levels may affect various aspects of immune function in M. galloprovincialis, acting as stressor that can compromise the general welfare.


Assuntos
Exposição Ambiental , Éteres Difenil Halogenados/toxicidade , Mytilus/imunologia , Animais , Antibacterianos/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Hemócitos/efeitos dos fármacos , Hemócitos/metabolismo , Hemolinfa/efeitos dos fármacos , Hemolinfa/metabolismo , Hemolinfa/microbiologia , Membranas Intracelulares/efeitos dos fármacos , Membranas Intracelulares/metabolismo , Lisossomos/efeitos dos fármacos , Lisossomos/metabolismo , Microalgas/fisiologia , Mytilus/efeitos dos fármacos , Mytilus/microbiologia , Peptídeo Hidrolases/metabolismo , Análise de Sobrevida , Poluentes Químicos da Água/toxicidade
11.
PLoS Genet ; 15(8): e1008331, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31412019

RESUMO

Holometabolous insects stop feeding at the final larval instar stage and then undergo metamorphosis; however, the mechanism is unclear. In the present study, using the serious lepidopteran agricultural pest Helicoverpa armigera as a model, we revealed that 20-hydroxyecdysone (20E) binds to the dopamine receptor (DopEcR), a G protein-coupled receptor, to stop larval feeding and promote pupation. DopEcR was expressed in various tissues and its level increased during metamorphic molting under 20E regulation. The 20E titer was low during larval feeding stages and high during wandering stages. By contrast, the dopamine (DA) titer was high during larval feeding stages and low during the wandering stages. Injection of 20E or blocking dopamine receptors using the inhibitor flupentixol decreased larval food consumption and body weight. Knockdown of DopEcR repressed larval feeding, growth, and pupation. 20E, via DopEcR, promoted apoptosis; and DA, via DopEcR, induced cell proliferation. 20E opposed DA function by repressing DA-induced cell proliferation and AKT phosphorylation. 20E, via DopEcR, induced gene expression and a rapid increase in intracellular calcium ions and cAMP. 20E induced the interaction of DopEcR with G proteins αs and αq. 20E, via DopEcR, induced protein phosphorylation and binding of the EcRB1-USP1 transcription complex to the ecdysone response element. DopEcR could bind 20E inside the cell membrane or after being isolated from the cell membrane. Mutation of DopEcR decreased 20E binding levels and related cellular responses. 20E competed with DA to bind to DopEcR. The results of the present study suggested that 20E, via binding to DopEcR, arrests larval feeding and promotes pupation.


Assuntos
Ecdisterona/metabolismo , Proteínas de Insetos/metabolismo , Mariposas/fisiologia , Receptores Dopaminérgicos/metabolismo , Animais , Dopamina/metabolismo , Antagonistas de Dopamina/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Flupentixol/farmacologia , Técnicas de Silenciamento de Genes , Proteínas de Insetos/genética , Larva/efeitos dos fármacos , Larva/fisiologia , Muda/efeitos dos fármacos , Muda/fisiologia , Mariposas/efeitos dos fármacos , Interferência de RNA , Receptores Dopaminérgicos/genética , Células Sf9
12.
J Dairy Sci ; 102(11): 9781-9790, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31447167

RESUMO

A faster rate of infusion of propionic acid into the rumen of cows in the postpartum period increased meal size compared with a slower rate of infusion in a previous experiment. Because propionate is anaplerotic and stimulates oxidation of acetyl coenzyme A (CoA) in the liver, and hepatic oxidation has been linked to satiety, this result was opposite to our expected response. We then hypothesized that the faster rate of infusion might have saturated the pathway for propionate metabolism in hepatocytes resulting in lower first-pass extraction by the liver. Because we were measuring feeding behavior, we could not sample blood and liver tissue over time in that experiment. Therefore, to determine the temporal effects of propionic acid (PA) infusion on hepatic metabolism and plasma metabolites over the time course of a meal, we infused 1.25 mol of PA (2.5 L of 0.5M PA) over 5 min (FST) or 15 min (SLW) into the rumen. We evaluated response to PA infusions both before feeding, when ruminal PA production by rumen microbes is lower and hepatic acetyl CoA concentration is greater, and 4 h after feeding, when PA production is greater and hepatic acetyl CoA concentration is lower. Blood and liver samples were collected before, and after 5, 15, and 30 min of infusion. Contrary to our hypothesis, the rate of PA infusion into the rumen did not affect plasma propionate concentration, indicating the FST effects on feeding behavior were not because of a limitation on propionate uptake by the liver. However, FST increased plasma glucose and insulin concentrations faster than SLW, resulting in a reduction in plasma nonesterified fatty acid concentration during the time frame of meals. Decreased plasma nonesterified fatty acid concentration during infusion likely decreased the supply of acetyl CoA for oxidation in the liver. The FST treatment also increased fumarate concentration at 5 min after the initiation of infusion but did not affect oxaloacetate concentration compared with SLW, consistent with a limitation to propionate metabolism at that reaction. A metabolic bottleneck at the malate dehydrogenase reaction for FST compared with SLW would further contribute to a reduction in hepatic oxidation within the time frame of a meal, allowing greater meal size, consistent with the hepatic oxidation theory and our previous results.


Assuntos
Bovinos/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Propionatos/administração & dosagem , Acetilcoenzima A/metabolismo , Animais , Glicemia/análise , Ácidos Graxos não Esterificados/sangue , Feminino , Insulina/sangue , Lactação , Fígado/metabolismo , Oxirredução , Período Pós-Parto/efeitos dos fármacos , Rúmen/metabolismo , Saciação
13.
Fungal Biol ; 123(8): 601-610, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31345414

RESUMO

Oosporein was first identified from the insect pathogen Beauveria bassiana >50 y ago. Here, we investigate the insecticidal, anti-feedant and immunomodulation effects of oosporein produced by Beauveria caledonica on the forestry pest Hylobius abietis and model insect Galleria mellonella. We report a novel feedback induction mechanism regulating oosporein production in B. caledonica; exogenous oosporein induces the expression of the oosporein cluster, leading to increased abundance of oosporein biosynthetic enzymes, as shown by label-free quantitative proteomics. Oosporein did not have an anti-feedant effect on H. abietis adults - on the contrary, insects exposed to oosporein-treated food fed more than those exposed to untreated food only. Injected oosporein did not kill insect larvae but increased susceptibility of H. abietis to a subsequent infection. Oosporein did not act as a contact toxin on H. abietis adults and G. mellonella larvae at the concentrations tested. Therefore, it appears that oosporein promotes infection rather than directly killing insects; this could be mediated both by a reduction in haemocyte numbers and by alterations to the humoral immune system. This work makes a case for future research into the potential use of B. caledonica as a biocontrol agent through combinations with oosporein or with enhanced production of oosporein.


Assuntos
Beauveria/metabolismo , Benzoquinonas/metabolismo , Benzoquinonas/toxicidade , Inseticidas/metabolismo , Inseticidas/toxicidade , Gorgulhos/microbiologia , Animais , Beauveria/química , Beauveria/patogenicidade , Vias Biossintéticas , Comportamento Alimentar/efeitos dos fármacos , Feminino , Proteínas Fúngicas/genética , Proteínas Fúngicas/metabolismo , Masculino , Virulência , Gorgulhos/fisiologia
14.
Amino Acids ; 51(8): 1129-1152, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31302780

RESUMO

Animals at the neonatal stage have to eat more to support better growth and health. However, it is difficult to understand the mechanism of feeding during an early stage of life in the brain of the rodent model. Chickens are precocial and they can look for their food by themselves right after hatching. Neonatal chicks have a relatively large-sized brain; therefore, the drugs are easy to administer centrally and changes in food intake can be clearly monitored. Sleeping status, which affects food intake, can be estimated from the posture. The closest vertebrate outgroup to mammals is birds, but it was reported that the organization of the human genome is closer to that of the chicken than the mouse. Thus, it is important to understand the central mechanism of feeding regulation in the neonatal chicks. In neuropeptides, the number of candidates as the orexigenic factor was less than those as the anorexigenic factor, even at an early growth stage. Some of the neuropeptides have reverse effects, e.g., ghrelin and prolactin releasing peptides, or no effects compared to the effects confirmed in mammals. Some of the genetic differences between meat-type (broiler) and layer-type chickens would explain the difference in food intake. On the other hand, it was difficult to explain the feeding mechanism by neuropeptides alone, as neonatal chicks have a repeated feeding, sleeping, and resting behavior within a short period. Some of the amino acids and their metabolites act centrally to regulate feeding with sedative and hypnotic effects. In conclusion, endogenous neuropeptides and endogenous and/or exogenous nutrients like amino acids collaborate to regulate feeding behavior in neonatal chicks.


Assuntos
Aminoácidos/farmacologia , Ingestão de Alimentos/fisiologia , Comportamento Alimentar/fisiologia , Neuropeptídeos/farmacologia , Animais , Animais Recém-Nascidos , Galinhas , Ingestão de Alimentos/efeitos dos fármacos , Comportamento Alimentar/efeitos dos fármacos
15.
Sci Total Environ ; 689: 413-421, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31279188

RESUMO

Microplastics (1-1000 µm) are ubiquitous in the marine, freshwater and terrestrial environments. These microsized plastics are considered freshwater pollutants of emerging concern, although the impacts on organisms and ecosystems are not yet clear. In particular, effects of microplastics on freshwater aquatic plants and the fate of microplastics in the freshwater trophic chain remain largely unexplored. Here we demonstrate that 10-45 µm polyethylene (PE) microplastics can strongly adsorb to all surfaces of the duckweed species Lemna minor. Despite adsorbance of up to 7 PE microplastics per mm2, seven day exposure experiments showed that photosynthetic efficiency and plant growth are not affected by microplastics. Rather, dense surface coverage suggests L. minor as a potential vector for the trophic transfer of microplastics. Here we show that the freshwater amphipod Gammarus duebeni can ingest 10-45 µm PE microplastics by feeding on contaminated L. minor. In this study, ingestion of microplastics had no apparent impact on amphipod mortality or mobility after 24 or 48 h exposure. Yet, the feeding study showed that the fate of microplastics in the environment may be complex, involving both plant adsorbance and trophic transfer.


Assuntos
Anfípodes/efeitos dos fármacos , Araceae/efeitos dos fármacos , Polietileno/efeitos adversos , Poluentes Químicos da Água/efeitos adversos , Anfípodes/fisiologia , Animais , Araceae/crescimento & desenvolvimento , Comportamento Alimentar/efeitos dos fármacos
16.
Bioengineered ; 10(1): 292-305, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31284815

RESUMO

In the present study, Probit, Cauchy Fractional and three types of Log methods, i.e., Logit, Log-log, and Complementary log-log were employed to model the feeding deterrence of the lesser grain borer, Rhyzopertha dominica (F) (Coleoptera: Bostrichidae), when fed latex protein, crude flavonoid fraction, 3-O-rutinosides of quercetin, kaempferol and isorhamnetin, isolated from Calotropis procera (Ait.) (Gentianales: Asclepiadaceae). A nutritional study with treated flour discs at sub-lethal concentrations indicated that the tested natural products negatively affected the feeding behavior of the lesser grain borer, causing high feeding deterrent indices. Our results assure that Probit, Logit and Clog-log model the feeding deterrent indices with high goodness of fit. The models aim to support the management of the test insect when fed grains treated with sub-lethal doses of the tested phytochemicals in order to develop a viable, precise and long-term strategy to minimize the excessive reliance on the chemical pesticides currently in use.


Assuntos
Produtos Biológicos/farmacologia , Calotropis/química , Besouros/efeitos dos fármacos , Quempferóis/farmacologia , Modelos Estatísticos , Quercetina/análogos & derivados , Quercetina/farmacologia , Animais , Besouros/fisiologia , Grão Comestível/parasitologia , Comportamento Alimentar/efeitos dos fármacos , Comportamento Alimentar/fisiologia , Glicosídeos/farmacologia , Larva/efeitos dos fármacos , Larva/fisiologia , Componentes Aéreos da Planta/química , Extratos Vegetais/química , Triticum/parasitologia
17.
Gen Comp Endocrinol ; 282: 113214, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31271760

RESUMO

The optic tectum rapidly inhibits food intake when a visual threat is present. Anatomical and electrophysiological evidence support a role for neuropeptide Y (NPY), originating from cells in the thalamus, in the tectal inhibition of prey capture. Here we test the hypothesis that tectal NPY receptor type 2 (NPY2R) influences prey-capture and predator-avoidance responses in the African clawed frog, Xenopus laevis. We tested two questions: 1) Does tectal NPY administration decrease food intake and alter prey-capture behavior? 2) Does tectal administration of a NPY2R antagonist increase food intake, alter prey-capture behavior, and alter predator avoidance behavior? NPY microinjected bilaterally into the tecta failed to significantly alter food intake at any dose tested, although predator presence significantly reduced food intake. However, NPY differentially altered discrete components of prey capture including increasing the latency to contact food and reducing the amount of time in contact with food. These effects were blocked by the NPY2R antagonist BIIE0246. Additionally, BIIE0246 elevated food intake on its own after bilateral tectal microinjection. Furthermore, BIIE0246 reversed the reduction of food intake caused by exposure to a predator. Overall, these findings indicate that tectal NPY2R activation causes frogs to consume food more quickly, which may be adaptive in predator-rich environments. Blocking tectal NPY2R increases baseline food intake and reduces or eliminates predator-induced changes in prey capture and food intake.


Assuntos
Sistemas Neurossecretores/metabolismo , Comportamento Predatório , Receptores de Neuropeptídeo Y/metabolismo , Colículos Superiores/metabolismo , Xenopus laevis/metabolismo , Animais , Arginina/análogos & derivados , Arginina/farmacologia , Benzazepinas/farmacologia , Comportamento Alimentar/efeitos dos fármacos , Feminino , Neuropeptídeo Y/farmacologia , Sistemas Neurossecretores/efeitos dos fármacos , Comportamento Predatório/efeitos dos fármacos , Colículos Superiores/efeitos dos fármacos , Suínos
18.
Nutrients ; 11(8)2019 Jul 26.
Artigo em Inglês | MEDLINE | ID: mdl-31357443

RESUMO

The purpose of this study was to explore the antidepressant-like effects of vitamin D3 at different doses (1.0, 2.5, and 5.0 mg/kg sc) on a model of depression produced by chronic unpredictable mild stress (CUMS) for 28 days in long-term (3 months) ovariectomized (OVX) adult rats. Sucrose preference (SPT), forced swimming (FST) and open-field (OFT) tests were conducted to examine the depression-like state. Serum corticosterone/adrenocorticotrophic hormone (ACTH) levels and hippocampal brain-derived neurotrophic factor (BDNF) and neurotrophin (NT)-3/NT-4 expressions by ELISA kits and/or western blotting were determined to assess the possible mechanisms of the vitamin D3 effects on the depression-like profile in long-term OVX rats subjected to CUMS. The results showed that vitamin D3 (5.0 mg/kg), as well as fluoxetine treatment, considerably reversed the depression-like state in the SPT and FST, decreased serum corticosterone/ACTH levels, and increased BDNF and NT-3/NT-4 levels in the hippocampus of long-term OVX rats compared to OVX rats with CUMS (p < 0.05). Thus, a high dose of vitamin D3 (5.0 mg/kg sc) could improve the depression-like profile in long-term OVX adult female rats subjected to the CUMS procedure, which might be mediated by the regulation of BDNF and the NT-3/NT-4 signaling pathways in the hippocampus, as well as the corticosterone/ACTH levels of the blood serum.


Assuntos
Antidepressivos/farmacologia , Comportamento Animal/efeitos dos fármacos , Fator Neurotrófico Derivado do Encéfalo/sangue , Colecalciferol/farmacologia , Depressão/tratamento farmacológico , Hipocampo/efeitos dos fármacos , Fatores de Crescimento Neural/sangue , Neurotrofina 3/sangue , Ovariectomia , Estresse Psicológico/tratamento farmacológico , Hormônio Adrenocorticotrópico/sangue , Animais , Biomarcadores/sangue , Doença Crônica , Corticosterona/sangue , Depressão/sangue , Depressão/psicologia , Modelos Animais de Doenças , Comportamento Alimentar/efeitos dos fármacos , Feminino , Hipocampo/metabolismo , Hipocampo/fisiopatologia , Locomoção/efeitos dos fármacos , Ratos Wistar , Estresse Psicológico/sangue , Estresse Psicológico/fisiopatologia , Estresse Psicológico/psicologia , Fatores de Tempo
19.
Nutrients ; 11(6)2019 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-31208031

RESUMO

BACKGROUND: During activity-based anorexia (ABA) in mice, enhanced paracellular permeability and reduced protein synthesis have been shown in the colon while the gut-brain axis has received increasing attention in the regulation of intestinal and mood disorders that frequently occur during anorexia nervosa, a severe eating disorder for which there is no specific treatment. In the present study, we assessed the effects of oral glutamine (Gln) or branched-chain amino acids (BCAA) supplementation during ABA to target intestinal functions, body composition and feeding behavior. METHODS: C57BL/6 male mice were randomized in Control (CTRL) and ABA groups. After ABA induction, mice received, or not, either 1% Gln or 2.5% BCAA (Leu, Ile, Val) for one week in drinking water. RESULTS: Neither Gln nor BCAA supplementation affected body weight and body composition, while only Gln supplementation slightly increased food intake. ABA mice exhibited increased paracellular permeability and reduced protein synthesis in the colonic mucosa. Oral Gln restored colonic paracellular permeability and protein synthesis and increased the mucin-2 mRNA level, whereas BCAA did not affect colonic parameters. CONCLUSION: In conclusion, oral Gln specifically improves colonic response during ABA. These data should be further confirmed in AN patients.


Assuntos
Aminoácidos de Cadeia Ramificada/farmacologia , Anorexia/tratamento farmacológico , Suplementos Nutricionais , Glutamina/farmacologia , Mucosa Intestinal/efeitos dos fármacos , Animais , Anorexia/fisiopatologia , Composição Corporal/efeitos dos fármacos , Colo/efeitos dos fármacos , Colo/fisiopatologia , Comportamento Alimentar/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Permeabilidade/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos
20.
Chemosphere ; 232: 424-429, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31158637

RESUMO

With the growth of both the pharmaceutical industry and the human population and longevity, more drugs are used and processed each day. Inevitably, these pharmaceuticals enter wastewater through human excretion and improper disposal of leftovers. One such medication, diltiazem, a calcium channel blocker, is of importance due to its widespread consumption, and prevalence in aquatic environments. To study the sub-lethal effects of diltiazem on aquatic animals, we investigated its impacts no feeding behaviour, heart rate, respiration, growth, and reproduction of a bioindicator species, Daphnia magna. When exposed to environmentally relevant concentrations, D. magna increased their heart rate by 12% and oxygen consumption by 48%. However, exposure did not have any effects on thoracic limb movement frequency or peristalsis (i.e. feeding behaviour). Individuals exposed to diltiazem for a longer duration (16 days) showed a 44% decrease in lipid reserves and produced between 17 and 28% fewer neonates which were 10-12% larger. Our study demonstrated that exposure to diltiazem creates an energy imbalance in D. magna which could, in the long run, influence their populations.


Assuntos
Cálcio/metabolismo , Daphnia , Diltiazem/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Daphnia/efeitos dos fármacos , Daphnia/crescimento & desenvolvimento , Daphnia/fisiologia , Comportamento Alimentar/efeitos dos fármacos , Frequência Cardíaca/efeitos dos fármacos , Reprodução/efeitos dos fármacos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA