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1.
Braz. j. biol ; 83: e244718, 2023. graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1278533

RESUMO

Abstract The objective of this study was to evaluate the activity of antioxidant enzymes, the functioning of the photosystem II and quality of C. xanthocarpa seedlings cultivated under intermittent water deficit and shading levels and the influence of shading on recovery potential after suspension of the stress conditions. The seedlings were subjected to three levels of shading (0, 30, and 70%), six periods of evaluation (start: 0 days; 1st and 2nd photosynthesis zero: 1st and 2nd P0; 1st and 2nd recovery: 1stand 2nd REC; and END), and two forms of irrigation (control: periodically irrigated to maintain 70% substrate water retention capacity, and intermittent irrigation: suspension of irrigation). The plants subjected to intermittent irrigation conditions at 0% shading showed a reduction in water potential (Ψw) and potential quantum efficiency of photosystem II (Fv/Fm) and maximum efficiency of the photochemical process (Fv/F0) and an increase in basal quantum production of the non-photochemical processes (F0/Fm). Superoxide dismutase (SOD) activity was higher in the leaves than in the roots. The C. xanthocarpa is a species sensitive to water deficit but presents strategies to adapt to an environment under temporary water restriction, which are more temporary are most efficient under shading. The seedlings with water deficit at all levels of shading exhibited higher protective antioxidant activity and lower quality at 0% shading. The shading minimizes prevents permanent damage to the photosystem II and after the re-irrigation, the evaluated characteristics showed recovery with respect to the control group, except POD and SOD activities in the leaves.


Resumo O objetivo deste estudo foi avaliar a atividade de enzimas antioxidantes, o funcionamento do fotossistema II e a qualidade de mudas de C. xanthocarpa cultivadas sob déficit hídrico intermitente e níveis de sombreamento e a influência do sombreamento sobre o potencial de recuperação após suspensão das condições de estresse. As mudas foram submetidas a três níveis de sombreamento (0, 30 e 70%), seis períodos de avaliação (início: 0 dias; 1ª e 2ª fotossíntese zero: 1ª e 2ª P0; 1ª e 2ª recuperação: 1ª e 2ª REC; e final), e duas formas de irrigação (controle: periodicamente irrigado para manter 70% da capacidade de retenção de água do substrato, e irrigação intermitente: suspensão da irrigação). As plantas submetidas às condições de irrigação intermitente a 0% de sombreamento apresentaram redução do potencial hídrico (Ψw) e eficiência quântica potencial do fotossistema II (Fv/Fm) e máxima eficiência do processo fotoquímico (Fv/F0) e aumento da produção quantica basal dos processos não fotoquímicos (F0/Fm). A atividade da superóxido dismutase (SOD) foi maior nas folhas do que nas raízes. C. xanthocarpa é uma espécie sensível ao déficit hídrico, mas apresenta estratégias para se adaptar a um ambiente com restrição hídrica temporária, sendo mais eficientes sob sombreamento. As mudas com déficit hídrico em todos os níveis de sombreamento exibiram maior atividade antioxidante protetora e menor qualidade no sombreamento 0%. O sombreamento minimiza danos permanentes ao fotossistema II e após a re-irrigação, as características avaliadas apresentaram recuperação em relação ao grupo controle, exceto atividades de POD e SOD nas folhas.

2.
Braz J Biol ; 83: e244718, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161459

RESUMO

The objective of this study was to evaluate the activity of antioxidant enzymes, the functioning of the photosystem II and quality of C. xanthocarpa seedlings cultivated under intermittent water deficit and shading levels and the influence of shading on recovery potential after suspension of the stress conditions. The seedlings were subjected to three levels of shading (0, 30, and 70%), six periods of evaluation (start: 0 days; 1st and 2nd photosynthesis zero: 1st and 2nd P0; 1st and 2nd recovery: 1stand 2nd REC; and END), and two forms of irrigation (control: periodically irrigated to maintain 70% substrate water retention capacity, and intermittent irrigation: suspension of irrigation). The plants subjected to intermittent irrigation conditions at 0% shading showed a reduction in water potential (Ψw) and potential quantum efficiency of photosystem II (Fv/Fm) and maximum efficiency of the photochemical process (Fv/F0) and an increase in basal quantum production of the non-photochemical processes (F0/Fm). Superoxide dismutase (SOD) activity was higher in the leaves than in the roots. The C. xanthocarpa is a species sensitive to water deficit but presents strategies to adapt to an environment under temporary water restriction, which are more temporary are most efficient under shading. The seedlings with water deficit at all levels of shading exhibited higher protective antioxidant activity and lower quality at 0% shading. The shading minimizes prevents permanent damage to the photosystem II and after the re-irrigation, the evaluated characteristics showed recovery with respect to the control group, except POD and SOD activities in the leaves.


Assuntos
Plântula , Água , Antioxidantes , Fotossíntese , Folhas de Planta
3.
J Dairy Sci ; 103(5): 4588-4605, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32113759

RESUMO

Staphylococcus aureus is one of the pathogens most frequently isolated from cases of mastitis worldwide. To decrease the effect of S. aureus mastitis in dairy farming, alternative strategies for controlling mastitis are needed that depend on a better knowledge of cow-to-cow variations in S. aureus antibody production. The present study sought to explore the diversity of S. aureus antibodies produced by dairy cows with a distinct mastitis history and vaccinated with a polyvalent mastitis vaccine. We obtained protein extracts from S. aureus isolates derived from persistent subclinical mastitis. Proteins were fractionated using 2-dimensional gel electrophoresis and Western blotting. Then, Western blotting membranes were exposed to sera from 24 dairy cows that had been divided into the following groups: vaccinated dairy cows that were infected with S. aureus, further subdivided according to whether they (a) remained infected by S. aureus or (b) recovered from the intramammary infection; unvaccinated dairy cows infected with S. aureus; and vaccinated healthy dairy cows with no history of S. aureus mastitis. Proteins found to be reactive by Western blot were identified by mass spectrometry (MALDI/TOF-TOF). Our most important finding was that F0F1 ATP synthase subunit α, succinyl-diaminopimelate desuccinylase, and cysteinyl-tRNA synthetase were potential candidate proteins for the prevention of S. aureus mastitis. This study strengthens the notion that variations among animals should not be ignored and shows that the heterogeneity of antibody production against anti-staphylococcal antigens in animals may enable the identification of new immunotherapy targets.


Assuntos
Anticorpos Antibacterianos/sangue , Mastite Bovina/imunologia , Infecções Estafilocócicas/veterinária , Vacinas Antiestafilocócicas/administração & dosagem , Staphylococcus aureus/imunologia , Animais , Anticorpos Antibacterianos/imunologia , Bovinos , Feminino , Humanos , Mastite Bovina/microbiologia , Mastite Bovina/prevenção & controle , Leite , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Vacinas Antiestafilocócicas/imunologia
4.
Horm Behav ; 118: 104658, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31874139

RESUMO

The aim of the present study was to determine whether the TRPV1 channel is involved in the onset of sodium appetite. For this purpose, we used TRPV1-knockout mice to investigate sodium depletion-induced drinking at different times (2/24 h) after furosemide administration combined with a low sodium diet (FURO-LSD). In sodium depleted wild type and TRPV1 KO (SD-WT/SD-TPRV1-KO) mice, we also evaluated the participation of other sodium sensors, such as TPRV4, NaX and angiotensin AT1-receptors (by RT-PCR), as well as investigating the pattern of neural activation shown by Fos immunoreactivity, in different nuclei involved in hydromineral regulation. TPRV1 SD-KO mice revealed an increased sodium preference, ingesting a higher hypertonic cocktail in comparison with SD-WT mice. Our results also showed in SD-WT animals that SFO-Trpv4 expression increased 2 h after FURO-LSD, compared to other groups, thus supporting a role of SFO-Trpv4 channels during the hyponatremic state. However, the SD-TPRV1-KO animals did not show this early increase, and maybe as a consequence drank more hypertonic cocktail. Regarding the SFO-NaX channel expression, in both genotypes our findings revealed a reduction 24 h after FURO-LSD. In addition, there was an increase in the OVLT-NaX expression of SD-WT 24 h after FURO-LSD, suggesting the participation of OVLT-NaX channels in the appearance of sodium appetite, possibly as an anticipatory response in order to limit sodium intake and to induce thirst. Our work demonstrates changes in the expression of different osmo­sodium-sensitive channels at specific nuclei, related to the body sodium status in order to stimulate an adequate drinking.


Assuntos
Apetite/genética , Encéfalo/metabolismo , Dieta Hipossódica , Sódio na Dieta/administração & dosagem , Canais de Cátion TRPV/fisiologia , Animais , Apetite/efeitos dos fármacos , Dieta Hipossódica/efeitos adversos , Ingestão de Líquidos/efeitos dos fármacos , Ingestão de Líquidos/genética , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/genética , Furosemida/farmacologia , Masculino , Camundongos , Camundongos da Linhagem 129 , Camundongos Endogâmicos C57BL , Camundongos Knockout , Sódio na Dieta/metabolismo , Canais de Cátion TRPV/genética , Canais de Cátion TRPV/metabolismo , Sede/efeitos dos fármacos , Sede/fisiologia
5.
Braz J Med Biol Res ; 52(10): e8491, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31618368

RESUMO

Considering the recognized role of thyroid hormones on the cardiovascular system during health and disease, we hypothesized that type 2 deiodinase (D2) activity, the main activation pathway of thyroxine (T4)-to-triiodothyronine (T3), could be an important site to modulate thyroid hormone status, which would then constitute a possible target for ß-adrenergic blocking agents in a myocardial infarction (MI) model induced by left coronary occlusion in rats. Despite a sustained and dramatic fall in serum T4 concentrations (60-70%), the serum T3 concentration fell only transiently in the first week post-infarction (53%) and returned to control levels at 8 and 12 weeks after surgery compared to the Sham group (P<0.05). Brown adipose tissue (BAT) D2 activity (fmol T4·min-1·mg ptn-1) was significantly increased by approximately 77% in the 8th week and approximately 100% in the 12th week in the MI group compared to that of the Sham group (P<0.05). Beta-blocker treatment (0.5 g/L propranolol given in the drinking water) maintained a low T3 state in MI animals, dampening both BAT D2 activity (44% reduction) and serum T3 (66% reduction in serum T3) compared to that of the non-treated MI group 12 weeks after surgery (P<0.05). Propranolol improved cardiac function (assessed by echocardiogram) in the MI group compared to the non-treated MI group by 40 and 57%, 1 and 12 weeks after treatment, respectively (P<0.05). Our data suggested that the beta-adrenergic pathway may contribute to BAT D2 hyperactivity and T3 normalization after MI in rats. Propranolol treatment maintained low T3 state and improved cardiac function additionally.


Assuntos
Tecido Adiposo Marrom/metabolismo , Antagonistas Adrenérgicos beta/administração & dosagem , Iodeto Peroxidase/metabolismo , Infarto do Miocárdio/metabolismo , Propranolol/administração & dosagem , Tiroxina/sangue , Tri-Iodotironina/sangue , Tecido Adiposo Marrom/efeitos dos fármacos , Animais , Modelos Animais de Doenças , Iodeto Peroxidase/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Tiroxina/efeitos dos fármacos , Tri-Iodotironina/efeitos dos fármacos
6.
Exp Physiol ; 104(12): 1754-1761, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31553087

RESUMO

NEW FINDINGS: What is the central question of this study? Can Na+ depletion mobilize Na+ from the skin reservoir in ovariectomized rats? Does oestrogen replacement change the amount and the dynamics of skin Na+ storage? Is the reduced salt appetite after Na+ depletion in ovariectomized rats with oestrogen replacement related to changes in the skin Na+ ? What is the main finding and its importance? This work demonstrated that acute body Na+ depletion induced by frusemide mobilized the osmotically inactive skin Na+ reservoir to become osmotically active. Oestrogen treatment decreased the induced Na+ intake in ovariectomized rats but did not modulate the inactive Na+ reservoir in control conditions or its mobilization induced by Na+ depletion. ABSTRACT: Oestradiol, which is an important hormone for water and electrolyte balance, also has a role in the inhibition of induced Na+ appetite. Sodium can be stored in the skin in osmotically active or inactive forms, and this skin Na+ reservoir may be involved in the control of body Na+ levels during physiopathological challenges. In this study, we investigated whether the effect of sodium depletion by frusemide can mobilize Na+ from the skin reservoir and whether oestradiol replacement changes or mobilizes the Na+ reserves in the skin. Ovariectomized Wistar rats were treated with vehicle or oestradiol for 7 days to evaluate the effects of oestrogen on the hydroelectrolyte balance, intake responses and skin Na+ and water content in basal conditions. Furthermore, the effects of oestrogen were evaluated after 24 h frusemide-induced whole-body Na+ depletion. Oestradiol-replaced rats exhibited reduced water intake without any significant changes in salt intake, Na+ excretion or water and Na+ skin content in basal conditions. After sodium depletion, both vehicle- and oestradiol-treated rats exhibited an increase in the osmotically active skin Na+ , which was associated with a decrease of the inactive skin Na+ reservoir. Oestrogen decreased the hypertonic saline intake induced by Na+ depletion, but it was not associated with any significant changes in the skin Na+ reservoir. Thus, sodium depletion is able to change the inactive-active skin Na+ reservoir balance. However, the oestrogenic modulation of sodium appetite after Na+ depletion is probably not related to the action of this hormone in the skin Na+ reservoir balance.


Assuntos
Estradiol/farmacologia , Hiponatremia/induzido quimicamente , Hiponatremia/metabolismo , Pele/metabolismo , Inibidores de Simportadores de Cloreto de Sódio e Potássio/toxicidade , Sódio/deficiência , Animais , Estradiol/uso terapêutico , Feminino , Furosemida/toxicidade , Hiponatremia/tratamento farmacológico , Ovariectomia/efeitos adversos , Ovariectomia/tendências , Ratos , Ratos Wistar , Pele/efeitos dos fármacos , Cloreto de Sódio na Dieta/administração & dosagem
7.
Braz. j. med. biol. res ; 52(10): e8491, 2019. tab, graf
Artigo em Inglês | LILACS-Express | LILACS | ID: biblio-1039254

RESUMO

Considering the recognized role of thyroid hormones on the cardiovascular system during health and disease, we hypothesized that type 2 deiodinase (D2) activity, the main activation pathway of thyroxine (T4)-to-triiodothyronine (T3), could be an important site to modulate thyroid hormone status, which would then constitute a possible target for β-adrenergic blocking agents in a myocardial infarction (MI) model induced by left coronary occlusion in rats. Despite a sustained and dramatic fall in serum T4 concentrations (60-70%), the serum T3 concentration fell only transiently in the first week post-infarction (53%) and returned to control levels at 8 and 12 weeks after surgery compared to the Sham group (P<0.05). Brown adipose tissue (BAT) D2 activity (fmol T4·min-1·mg ptn-1) was significantly increased by approximately 77% in the 8th week and approximately 100% in the 12th week in the MI group compared to that of the Sham group (P<0.05). Beta-blocker treatment (0.5 g/L propranolol given in the drinking water) maintained a low T3 state in MI animals, dampening both BAT D2 activity (44% reduction) and serum T3 (66% reduction in serum T3) compared to that of the non-treated MI group 12 weeks after surgery (P<0.05). Propranolol improved cardiac function (assessed by echocardiogram) in the MI group compared to the non-treated MI group by 40 and 57%, 1 and 12 weeks after treatment, respectively (P<0.05). Our data suggested that the beta-adrenergic pathway may contribute to BAT D2 hyperactivity and T3 normalization after MI in rats. Propranolol treatment maintained low T3 state and improved cardiac function additionally.

8.
J Econ Entomol ; 111(3): 1042-1047, 2018 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-29474651

RESUMO

Sublethal insecticide exposure may affect foraging of insects, including natural enemies, although the subject is usually neglected. The lady beetle Eriopis connexa (Germar, 1824) (Coleoptera: Coccinelidae) is an important predator of aphids with existing pyrethroid-resistant populations that are undergoing scrutiny for potential use in pest management systems characterized by frequent insecticide use. However, the potential effect of sublethal pyrethroid exposure on this predator's foraging activity has not yet been assessed and may compromise its use in biological control. Therefore, our objective was to assess the effect of sublethal lambda-cyhalothrin exposure on three components of the prey foraging activity (i.e., walking, and prey searching and handling), in both pyrethroid-susceptible and -resistant adults of E. connexa. Both lady beetle populations exhibited similar walking patterns without insecticide exposure in noncontaminated arenas, but in partially contaminated arenas walking differed between strains, such that the resistant insects exhibited greater walking activity. Behavioral avoidance expressed as repellence to lambda-cyhalothrin was not observed for either the susceptible or resistant populations of E. connexa, but the insecticide caused avoidance by means of inducing irritability in 40% of the individuals, irrespective of the strain. Insects remained in the insecticide-contaminated portion of the arena for extended periods resulting in greater exposure. Although lambda-cyhalothrin exposure did not affect prey searching by susceptible lady beetles, prey searching was extended for exposed resistant predators. In contrast, prey handling was not affected by population or by lambda-cyhalothrin exposure. Thus, sublethal exposure to the insecticide in conjunction with the insect resistance profile can affect prey foraging with pyrethroid-exposed resistant predators exhibiting longer prey searching time associated with higher walking activity reducing its predatory performance.


Assuntos
Besouros/efeitos dos fármacos , Inseticidas/toxicidade , Nitrilas/toxicidade , Comportamento Predatório/efeitos dos fármacos , Piretrinas/toxicidade , Animais , Afídeos , Brasil , Besouros/fisiologia , Resistência a Inseticidas
9.
Oral Dis ; 24(4): 657-663, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-28994220

RESUMO

OBJECTIVE: To study the incidence and magnitude of bacteremia after dental extraction and supragingival scaling. SUBJECTS AND METHODS: Blood samples were taken before and 5 and 30 min after dental extraction and supragingival scaling from individuals at high (n = 44) or negligible risk (n = 51) for infective endocarditis. The former received prophylactic antibiotic therapy. Samples were subjected to aerobic and anaerobic culture and quantitative real-time polymerase chain reaction to determine the incidence of bacteremia and total bacterial levels. RESULTS: Patients who did not receive prophylactic antibiotic therapy had a higher incidence of positive blood cultures (30% 5 min after extraction) than patients who received prophylactic antibiotic therapy (0% 5 min after extraction; p < .01). Molecular analysis did not reveal significant differences in the incidence or magnitude of bacteremia between the two patient groups either 5 or 30 min after each of the procedures evaluated. Extraction was associated with higher incidence of bacteremia than supragingival scaling by blood culture (p = .03) and molecular analysis (p = .05). CONCLUSIONS: Molecular methods revealed that dental extraction and supragingival scaling were associated with similar incidence of bacteremia in groups receiving or not prophylactic antibiotic therapy. However, blood culture revealed that antibiotic therapy reduced viable cultivable bacteria in the bloodstream in the extraction group.


Assuntos
Antibioticoprofilaxia , Bacteriemia/etiologia , Raspagem Dentária/efeitos adversos , Endocardite Bacteriana/prevenção & controle , Extração Dentária/efeitos adversos , Adolescente , Adulto , Idoso , Carga Bacteriana , Hemocultura , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Adulto Jovem
10.
J Neuroendocrinol ; 29(9)2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28836382

RESUMO

Sodium appetite is regulated by several signalling molecules, among which angiotensin II (Ang II) serves as a key driver of robust salt intake by binding to Ang II type 1 receptors (AT1R) in several regions in the brain. The activation of these receptors recruits the mitogen-activated protein kinase (MAPK) pathway, which has previously been linked to Ang II-induced increases in sodium appetite. Thus, we addressed the involvement of MAPK signalling in the induction of sodium appetite after 4 days of low-sodium diet consumption. An increase in extracellular signal-regulated kinase (ERK) phosphorylation in the laminae terminalis and mediobasal hypothalamus was observed after low-sodium diet consumption. This response was reduced by i.c.v. microinjection of an AT1R antagonist into the laminae terminalis but not the hypothalamus. This result indicates that low-sodium diet consumption activates the MAPK pathway via Ang II/AT1R signalling on the laminae terminalis. On the other hand, activation of the MAPK pathway in the mediobasal hypothalamus after low-sodium diet consumption appears to involve another extracellular mediator. We also evaluated whether a low-sodium diet could increase the sensitivity for Ang II in the brain and activate the MAPK pathway. However, i.c.v. injection of Ang II increased ERK phosphorylation on the laminae terminalis and mediobasal hypothalamus; this increase achieved a response magnitude similar to those observed in both the normal and low-sodium diet groups. These data indicate that low-sodium diet consumption for 4 days is insufficient to change the ERK phosphorylation response to Ang II in the brain. To investigate whether the MAPK pathway is involved in sodium appetite after low-sodium diet consumption, we performed i.c.v. microinjections of a MAPK pathway inhibitor (PD98059). PD98059 inhibited both saline and water intake after low-sodium diet consumption. Thus, the MAPK pathway is involved in promoting the sodium appetite after low-sodium diet consumption.


Assuntos
Apetite , Encéfalo/metabolismo , Proteína Quinase 1 Ativada por Mitógeno/metabolismo , Proteína Quinase 3 Ativada por Mitógeno/metabolismo , Sódio na Dieta , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Animais , Dieta Hipossódica , Masculino , Ratos Wistar , Receptor Tipo 1 de Angiotensina/metabolismo , Transdução de Sinais
11.
Neuroscience ; 322: 525-38, 2016 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-26951941

RESUMO

The angiotensin II (ANGII) receptor AT1 plays an important role in the control of hydromineral balance, mediating the dipsogenic and natriorexigenic effects and neuroendocrine responses of ANGII. While estradiol (E2) is known to modulate several actions of ANGII in the brain, the molecular and cellular mechanisms of the interaction between E2 and ANGII and its physiological role in the control of body fluids remain unclear. We investigated the influence of E2 (40 µg/kg) pretreatment and extracellular-signal-regulated kinase (ERK1/2) and c-Jun N-terminal kinase (JNK) cell signaling on the dipsogenic and natriorexigenic effects, as well as the neuroendocrine responses to angiotensinergic central stimulation in ovariectomized rats (OVX). We showed that the inhibitory effect of E2 on ANGII-induced water and sodium intake requires the ERK1/2 and JNK signaling pathways. On the other hand, E2 pretreatment prevents the ANGII-induced phosphorylation of ERK and JNK in the lamina terminalis. E2 therapy decreased oxytocin (OT) and vasopressin (AVP) secretion and decreased ERK1/2 phosphorylation in the supraoptic and paraventricular nuclei (SON and PVN, respectively). We found that the AVP secretion induced by ANGII required ERK1/2 signaling, but OT secretion did not involve ERK1/2 signaling. Taken together, these results demonstrate that E2 modulates ANGII-induced water and sodium intake and AVP secretion by affecting the ERK1/2 and JNK pathways in the lamina terminalis and ERK1/2 signaling in the hypothalamic nuclei (PVN and SON) in OVX rats.


Assuntos
Angiotensina II/metabolismo , Ingestão de Líquidos/fisiologia , Estradiol/metabolismo , Proteínas Quinases JNK Ativadas por Mitógeno/metabolismo , Sistema de Sinalização das MAP Quinases/fisiologia , Sódio na Dieta , Angiotensina II/administração & dosagem , Animais , Fármacos do Sistema Nervoso Central/administração & dosagem , Fármacos do Sistema Nervoso Central/metabolismo , Ingestão de Líquidos/efeitos dos fármacos , Estradiol/administração & dosagem , Feminino , Proteínas Quinases JNK Ativadas por Mitógeno/antagonistas & inibidores , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Ovariectomia , Ocitocina/metabolismo , Núcleo Hipotalâmico Paraventricular/efeitos dos fármacos , Núcleo Hipotalâmico Paraventricular/metabolismo , Distribuição Aleatória , Ratos Wistar , Núcleo Supraóptico/efeitos dos fármacos , Núcleo Supraóptico/metabolismo , Vasopressinas/metabolismo
12.
Parasite Immunol ; 35(7-8): 239-44, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23668415

RESUMO

Previously, we showed in Leishmania infections that extrinsic insulin-like growth factor (IGF)-I favored Leishmania proliferation and leishmaniasis development. In this study, the interaction of intrinsically expressed IGF-I and Leishmania (Leishmania) major in macrophages was addressed, and a key finding was the observation, using confocal microscopy, of the co-localization of IGF-I and parasites within macrophages. Following stimulation with interferon-γ (IFN-γ), which is known to inhibit IGF-I production in macrophages, we observed a reduction in the expression of both IGF-I mRNA and protein. This reduced expression was accompanied by a reduction in the cellular parasite load that was completely recovered with the addition of extrinsic IGF-I, which suggests an essential role for IGF-I in Leishmania growth.


Assuntos
Fator de Crescimento Insulin-Like I/metabolismo , Leishmania major/crescimento & desenvolvimento , Macrófagos/metabolismo , Macrófagos/parasitologia , Animais , Linhagem Celular Tumoral , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/farmacologia , Interferon gama/imunologia , Leishmania major/metabolismo , Camundongos , Microscopia Confocal , Carga Parasitária , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Proteínas Recombinantes/farmacologia
13.
Scand J Immunol ; 78(1): 79-84, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23578109

RESUMO

The understanding of the mechanisms involved in the immune response is of significant relevance to the control of tuberculosis (TB), especially in individuals living with patients with TB. To characterize the nitric oxide (NO) production and the Foxp3 marker expression in this population, peripheral blood mononuclear cells of intradomiciliary contacts of individuals with pulmonary tuberculosis with (CTb, susceptible) and without (STb, resistant) previous history of active infection were stimulated in vitro with Mycobacterium tuberculosis antigen (TbAg) and with the mitogen Concanavalin A for 24 and 48 h. The groups analysed did not present significant difference in the Foxp3 mRNA expression nor in the NO production. Negative correlation (P = 0.09) between NO and Foxp3 after a 48-h stimulation with TbAg was observed in the STb group. In this group, after a 24-h culture stimulated with TbAg (P = 0.03), this same correlation was observed. In comparison with the cytokines previously studied by our group (Cavalcanti et al., 2009), a positive correlation was observed between IL-10 and Foxp3 after a 48-h culture of cells from communicants susceptible to tuberculosis (STb) stimulated with TbAg (P = 0.04). Evaluating the entire population, a positive correlation was observed between the cytokine TNF-α and the Foxp3 marker in the cultures stimulated for 24 (P = 0.03) and 48 (P = 0.02) hours with TbAg. Therefore, considering the similarity in the exposure and the individual capacity of responding to the contact with M. tuberculosis, the present study contributes to the comprehension of the immune regulation in individuals living with patients with TB.


Assuntos
Fatores de Transcrição Forkhead/fisiologia , Leucócitos Mononucleares/metabolismo , Óxido Nítrico/biossíntese , Tuberculose Pulmonar/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Fatores de Transcrição Forkhead/genética , Humanos , Interferon gama/biossíntese , Masculino , Pessoa de Meia-Idade , RNA Mensageiro/análise
14.
Braz J Med Biol Res ; 46(4): 327-38, 2013 04.
Artigo em Inglês | MEDLINE | ID: mdl-23579631

RESUMO

Several forebrain and brainstem neurochemical circuitries interact with peripheral neural and humoral signals to collaboratively maintain both the volume and osmolality of extracellular fluids. Although much progress has been made over the past decades in the understanding of complex mechanisms underlying neuroendocrine control of hydromineral homeostasis, several issues still remain to be clarified. The use of techniques such as molecular biology, neuronal tracing, electrophysiology, immunohistochemistry, and microinfusions has significantly improved our ability to identify neuronal phenotypes and their signals, including those related to neuron-glia interactions. Accordingly, neurons have been shown to produce and release a large number of chemical mediators (neurotransmitters, neurohormones and neuromodulators) into the interstitial space, which include not only classic neurotransmitters, such as acetylcholine, amines (noradrenaline, serotonin) and amino acids (glutamate, GABA), but also gaseous (nitric oxide, carbon monoxide and hydrogen sulfide) and lipid-derived (endocannabinoids) mediators. This efferent response, initiated within the neuronal environment, recruits several peripheral effectors, such as hormones (glucocorticoids, angiotensin II, estrogen), which in turn modulate central nervous system responsiveness to systemic challenges. Therefore, in this review, we shall evaluate in an integrated manner the physiological control of body fluid homeostasis from the molecular aspects to the systemic and integrated responses.


Assuntos
Líquidos Corporais/fisiologia , Homeostase/fisiologia , Vias Neurais/fisiologia , Neurossecreção/fisiologia , Neurotransmissores/fisiologia , Transdução de Sinais/fisiologia , Animais , Mapeamento Encefálico , Humanos , Concentração Osmolar
15.
Braz. j. med. biol. res ; 46(4): 327-338, 05/abr. 2013.
Artigo em Inglês | LILACS | ID: lil-671387

RESUMO

Several forebrain and brainstem neurochemical circuitries interact with peripheral neural and humoral signals to collaboratively maintain both the volume and osmolality of extracellular fluids. Although much progress has been made over the past decades in the understanding of complex mechanisms underlying neuroendocrine control of hydromineral homeostasis, several issues still remain to be clarified. The use of techniques such as molecular biology, neuronal tracing, electrophysiology, immunohistochemistry, and microinfusions has significantly improved our ability to identify neuronal phenotypes and their signals, including those related to neuron-glia interactions. Accordingly, neurons have been shown to produce and release a large number of chemical mediators (neurotransmitters, neurohormones and neuromodulators) into the interstitial space, which include not only classic neurotransmitters, such as acetylcholine, amines (noradrenaline, serotonin) and amino acids (glutamate, GABA), but also gaseous (nitric oxide, carbon monoxide and hydrogen sulfide) and lipid-derived (endocannabinoids) mediators. This efferent response, initiated within the neuronal environment, recruits several peripheral effectors, such as hormones (glucocorticoids, angiotensin II, estrogen), which in turn modulate central nervous system responsiveness to systemic challenges. Therefore, in this review, we shall evaluate in an integrated manner the physiological control of body fluid homeostasis from the molecular aspects to the systemic and integrated responses.


Assuntos
Animais , Humanos , Líquidos Corporais/fisiologia , Homeostase/fisiologia , Vias Neurais/fisiologia , Neurossecreção/fisiologia , Neurotransmissores/fisiologia , Transdução de Sinais/fisiologia , Mapeamento Encefálico , Concentração Osmolar
16.
Eur J Pain ; 17(9): 1291-8, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23536325

RESUMO

BACKGROUND: Thyroid hormones (THs) play a crucial role in the development of several organic systems. An adequate support of maternal THs may be required to ensure a normal nociceptive function of offspring into adulthood. We investigated the impact of experimental gestational hypothyroidism (EGH) on nociceptive threshold and motor performance in the offspring at different post-natal days (PND) in both male and female rats. METHODS: EGH was induced by the administration of 0.02% methimazole (MMI) in the drinking water from the ninth day of gestation until birth. The offspring from MMI-treated dams (OMTDs) or from water-treated dams (OWTDs) were assessed for thermal and mechanical nociception using the tail-flick test and von Frey filaments, respectively. Both rota-rod and grip strength were used to assess motor function. RESULTS: OMTD had reduced thermal (p<0.05) but not mechanical threshold at all studied ages (60 and 120 PND). Sixty-day-old OMTD presented reduced latency to the tail-flick test (p=0.01). Grip strength in 120-day-old OMTD was reduced (p<0.01). However, only male OMTD presented a lower locomotor performance on the rota-rod test when analysed on the 60th PND (p<0.01). CONCLUSIONS: EGH promotes hypersensitivity to noxious thermal but not mechanical stimulus. Moreover, motor force is similarly reduced in male and female OMTDs, whereas motor performance is reduced only in mature male OMTD, suggesting the presence of a protective factor in females.


Assuntos
Hipotireoidismo/fisiopatologia , Atividade Motora/fisiologia , Nociceptividade/fisiologia , Dor/fisiopatologia , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Animais , Feminino , Hipotireoidismo/complicações , Masculino , Dor/etiologia , Medição da Dor , Estimulação Física , Gravidez , Ratos , Ratos Wistar
17.
Horm Behav ; 64(5): 847-55, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24396886

RESUMO

Estradiol (E2) plays an important role in controlling the homeostasis of body fluids. Several studies have reported the involvement of the hypothalamic pituitary adrenal axis (HPA) in the homeostatic control of hydromineral balance and the influence of estrogens on the modulation of this system. Nevertheless, until now, the physiological relevance of HPA axis activity on the hydromineral balance in females has not yet been fully elucidated. Therefore, the objective of the present study was to evaluate the effects of E2 (20 µg/animal) pretreatment on neuroendocrine and hydroelectrolyte changes induced by adrenalectomy (ADX) with or without glucocorticoid hormone replacement (corticosterone, CORT; 10 mg/kg) in ovariectomized rats (OVX). The results show that sodium appetite, natriuresis and the elevated plasma angiotensin II (ANG II) concentration induced by ADX were attenuated by E2 pretreatment. Additionally, a reduction of AT1 mRNA expression in the subfornical organ (SFO) and an increase in plasma atrial natriuretic peptide (ANP) concentrations by E2 pretreatment were observed. E2 pretreatment reversed the reduction in water intake induced by ADX in ADX CORT-replaced rats. Moreover, E2 pretreatment attenuated corticotropin releasing factor (CRF) mRNA expression in the paraventricular nucleus (PVN) induced by ADX. In contrast, E2 pretreatment increased CRF mRNA expression in the PVN in ADX CORT-replaced rats. Taken together, these results suggest that E2 has an important role in the modulation of behavioral and neuroendocrine responses involved in the maintenance of body fluid homeostasis in ADX rats with or without glucocorticoid replacement therapy.


Assuntos
Insuficiência Adrenal/metabolismo , Corticosterona/fisiologia , Estradiol/fisiologia , Minerais/metabolismo , Equilíbrio Hidroeletrolítico , Animais , Corticosterona/farmacologia , Ingestão de Líquidos/efeitos dos fármacos , Interações Medicamentosas , Estradiol/farmacologia , Feminino , Natriurese/efeitos dos fármacos , Ovariectomia , Ratos , Ratos Wistar , Sódio/metabolismo , Sede/efeitos dos fármacos , Equilíbrio Hidroeletrolítico/efeitos dos fármacos
18.
J Neuroendocrinol ; 25(3): 281-91, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23002791

RESUMO

The present study aimed to investigate the role of angiotensin II (Ang II) on sodium appetite in rats subjected to a normal or a low-sodium diet (1% or > 0.1% NaCl) for 4 days. During sodium restriction, a reduction in water intake, urinary volume and sodium excretion was observed. After a low-sodium diet, we observed decreased plasma protein concentrations and haematocrit associated with a slight reduction in arterial pressure, without any significant changes in heart rate, natraemia, corticotrophin-releasing hormone mRNA expression in the paraventricular nucleus and corticosterone levels. After providing hypertonic saline, there was an increase in saline intake followed by a small increase in water intake, resulting in an enhanced saline intake ratio and the recovery of arterial pressure. Sodium deprivation increased plasma but not brain Ang I and II concentrations. A low-sodium diet increased kidney renin and liver angiotensinogen mRNA levels but not lung angiotensin-converting enzyme mRNA expression. Moreover, Ang II type 1a receptor mRNA expression was increased in the subfornical organ and the dorsal raphe nucleus and decreased in the medial preoptic nuclei, without changes in the paraventricular nucleus and the nucleus of solitary tract after a low-sodium diet. Blockade of AT(1) receptors or brain Ang II synthesis led to a reduction in sodium intake after a low-sodium diet. Intracerebroventricular injection of Ang II led to a similar increase in sodium and water intake in the control and low-sodium diet groups. In conclusion, the results of the present study suggest that Ang II is involved in the increased sodium appetite after a low-sodium diet.


Assuntos
Angiotensina II/fisiologia , Dieta Hipossódica , Sódio/administração & dosagem , Animais , Masculino , Radioimunoensaio , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real
19.
Scand J Immunol ; 76(2): 175-80, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22537157

RESUMO

The influence of immune response on the treatment of American tegumentary leishmaniasis is pointed by several authors, and the existence of protective immunity in self-healed patients (SH) is also suggested. Thus, interferon-gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), interleukin (IL-) 10, IL-17, IL-22 and nitric oxide (NO) production was determined in PBMC culture supernatants from patients with active disease (AD) and after therapy, SH patients and healthy subjects, in response to the soluble antigen of Leishmania (Viannia) braziliensis. It was demonstrated that, during the active disease, there is a predominance of IFN-γ and TNF-α, indicating a proinflammatory phase of the response; IL-17 is also highlighted at this clinical state. Also, TNF-α was slightly increased in patients after therapy. NO secretion was noticed in SH individuals, while IL-17 appeared in low levels in these patients and seems to be regulated by NO. The presence of IL-10 was observed in all groups of patients. From this study, we can suggest that in the active disease and after clinical cure, with or without chemotherapy, specific cellular immunity takes part against Leishmania, but with some similarities between the clinical states. Thus, it indicates that the mediators herein described are necessary for the cure to occur.


Assuntos
Citocinas/imunologia , Leishmaniose Cutânea/imunologia , Óxido Nítrico/imunologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Células Cultivadas , Citocinas/biossíntese , Feminino , Humanos , Leishmaniose Cutânea/tratamento farmacológico , Masculino , Pessoa de Meia-Idade , Óxido Nítrico/biossíntese , Adulto Jovem
20.
Clin Exp Pharmacol Physiol ; 36(5-6): 495-500, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19673931

RESUMO

1. The use of angiotensin-converting enzyme (ACE) inhibitors during pregnancy is contraindicated because of their association with increased risks of fetopathy, including central nervous systems malformations. In addition, some reports have shown that renin-angiotensin system components are expressed differently during embryonic development and adulthood in the rat. 2. Because angiotensin II and its derivative peptides have been implicated in anxiety and modulation of nociception, the aim of the present study was to investigate whether inhibiting ACE during prenatal and neonatal periods would alter behavioural plasticity in adult male offspring rats. 3. Female Wistar rats were treated with captopril (2 mg/mL water; approximately 200 mg/kg per day) during pregnancy and lactation. At adulthood, the offspring were subjected to the open field, elevated plus maze, social interaction, forced swimming and tail flick tests. 4. Perinatal captopril treatment significantly increased ambulation (33%; P < 0.05) and decreased resting time (37.5%; P < 0.05) in the open field test. Perinatal captopril treatment did not alter any of the behavioural parameters of the elevated plus maze; however, captopril treatment did cause a significant increase in social interaction (75.3%; P < 0.05). In the forced swimming test, there was an increased latency period (102.9%; P < 0.001) and a decreased immobility period (38.7, P < 0.05) in rats treated with perinatal captopril. In the tail flick test, perinatal captopril treatment significantly reduced the latency time (26.3%; P < 0.01). 5. The data show that ACE inhibition during prenatal and neonatal periods affects behavioural responses in adult offspring rats, suggesting that ACE is required for the development of neural systems that are associated with adult anxiety and nociceptive behavioural responses.


Assuntos
Inibidores da Enzima Conversora de Angiotensina/efeitos adversos , Comportamento Animal/efeitos dos fármacos , Lactação , Prenhez , Efeitos Tardios da Exposição Pré-Natal/fisiopatologia , Algoritmos , Animais , Comportamento Animal/fisiologia , Captopril/efeitos adversos , Avaliação Pré-Clínica de Medicamentos , Feminino , Reação de Congelamento Cataléptica/efeitos dos fármacos , Lactação/efeitos dos fármacos , Lactação/fisiologia , Masculino , Exposição Materna/efeitos adversos , Aprendizagem em Labirinto/efeitos dos fármacos , Gravidez , Prenhez/efeitos dos fármacos , Efeitos Tardios da Exposição Pré-Natal/induzido quimicamente , Ratos , Ratos Wistar , Comportamento Social , Natação
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