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1.
Curr Vasc Pharmacol ; 21(4): 246-256, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37349999

RESUMO

BACKGROUND: We previously reported that endothelins (ETs) regulate tyrosine hydroxylase (TH) activity and expression in the olfactory bulb (OB) of normotensive and hypertensive animals. Applying an ET receptor type A (ETA) antagonist to the brain suggested that endogenous ETs bind to ET receptor type B (ETB) to elicit effects. OBJECTIVE: The aim of the present work was to evaluate the role of central ETB stimulation on the regulation of blood pressure (BP) and the catecholaminergic system in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. METHODS: DOCA-salt hypertensive rats were infused for 7 days with cerebrospinal fluid or IRL-1620 (ETB receptor agonist) through a cannula placed in the lateral brain ventricle. Systolic BP (SBP) and heart rate were recorded by plethysmography. The expression of TH and its phosphorylated forms in the OB were determined by immunoblotting, TH activity by a radioenzymatic assay, and TH mRNA by quantitative real-time polymerase chain reaction. RESULTS: Chronic administration of IRL-1620 decreased SBP in hypertensive rats but not in normotensive animals. Furthermore, the blockade of ETB receptors also decreased TH-mRNA in DOCA-salt rats, but it did not modify TH activity or protein expression. CONCLUSION: These findings suggest that brain ETs through the activation of ETB receptors contribute to SBP regulation in DOCA-salt hypertension. However, the catecholaminergic system in the OB does not appear to be conclusively involved although mRNA TH was reduced. Present and previous findings suggest that in this salt-sensitive animal model of hypertension, the OB contributes to chronic BP elevation.


Assuntos
Acetato de Desoxicorticosterona , Hipertensão , Ratos , Animais , Acetato de Desoxicorticosterona/farmacologia , Tirosina 3-Mono-Oxigenase/metabolismo , Tirosina 3-Mono-Oxigenase/farmacologia , Bulbo Olfatório/metabolismo , Hipertensão/induzido quimicamente , Hipertensão/metabolismo , Pressão Sanguínea , Endotelinas/metabolismo , Endotelinas/farmacologia , Receptor de Endotelina B/genética , Receptor de Endotelina B/metabolismo , RNA Mensageiro/metabolismo , Endotelina-1/genética , Endotelina-1/metabolismo , Endotelina-1/farmacologia , Receptor de Endotelina A/genética , Receptor de Endotelina A/metabolismo
2.
Environ Sci Pollut Res Int ; 29(35): 53482-53495, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35288853

RESUMO

Ground-cover vegetation attracts and harbors beneficial insects to the agrosystem, playing an important role in conservation biological control. Integrated pest management (IPM) program guidelines recommend the implantation of sowed or resident wild covers in perennial crops. Given the high-quality fruit requirements, even in IPM programs, insecticides can be required in citrus crops. This study presents, over a year, the levels of neonicotinoids (thiamethoxam and imidacloprid) in not-target ground-cover wildflowers growing spontaneously in citrus orchards after foliar treatment of citrus trees. The presence and persistence of these neonicotinoids in different wildflower species were studied. Concentrations of thiamethoxam and imidacloprid in whole wildflowers ranged from < method quantification limit (MQL) to 52.9 ng g-1 and from < MQL to 98.6 ng g-1, respectively. Thiamethoxam was more frequently detected than imidacloprid. Thiamethoxam and imidacloprid were detected up to 336 and 230 days after treatment, respectively. The highest detection frequencies (100%) and highest thiamethoxam and imidacloprid mean concentrations (26.0 ± 7.3 ng g-1 and 11.0 ± 10.6 ng g-1, respectively) occurred in wildflowers collected 9 days after the treatments. Since application, a clear decrease in the concentration of both compounds and differences in the accumulation depending on wildflower species were observed. Cross contamination was detected, indicating a transport from adjacent treated plots. Maintaining a cover crop in citrus orchards may lead to detrimental effects on non-target arthropods if these neonicotinoid compounds are used for pest control since they can entail a chronic exposure during at least 230 days for imidacloprid and 336 days for thiamethoxam.


Assuntos
Citrus , Inseticidas , Região do Mediterrâneo , Neonicotinoides , Nitrocompostos , Espanha , Tiametoxam , Árvores
3.
Eur J Pharmacol ; 885: 173543, 2020 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-32896551

RESUMO

Endothelins regulate catecholaminergic activity in the olfactory bulb (OB) in normotensive and hypertensive animals. Administration of an endothelin ETA receptor antagonist decreases blood pressure in deoxycorticosterone acetate-salt (DOCA-salt) rats along with a reduction in tyrosine hydroxylase (TH) activity and expression. In the present work, we sought to establish the role of brain endothelin ETB receptor on blood pressure regulation and its relationship with the catecholaminergic system within the OB of DOCA-Salt rats. Sprague-Dawley male rats were divided into control and DOCA-Salt groups. Blood pressure, heart rate and TH activity as well as neuronal nitric oxide synthase (nNOS) expression were assessed following IRL-1620 (selective endothelin ETB receptor agonist) applied to be brain. IRL-1620 significantly reduced systolic, diastolic, and mean arterial pressure in DOCA-Salt hypertensive rats. It also decreased TH activity, TH total and phosphorylated forms expression as well as its mRNA in the OB of hypertensive animals. The expression of phospho-Ser1417-nNOS, which reflects nNOS activation, was significantly decreased in the of OB of DOCA-salt rats, but it was enhanced by IRL-1620. These findings suggest that DOCA-Salt hypertension depends on endogenous central endothelin ETA receptor activity, rather than on ETB, and that low endothelin ETB stimulation is essential for blood pressure elevation in this animal model. The effect of endothelin ETA receptor antagonism may also result from endothelin ETB receptor overstimulation. The present study shows that endothelin receptors are involved in the regulation of TH in the OB and that such changes are likely implicated in the hemodynamic control and sympathetic outflow.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Hipertensão/tratamento farmacológico , Hipertensão/fisiopatologia , Bulbo Olfatório/efeitos dos fármacos , Receptor de Endotelina B/agonistas , Sistema Nervoso Simpático/efeitos dos fármacos , Animais , Desoxicorticosterona , Endotelinas/farmacologia , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/induzido quimicamente , Masculino , Óxido Nítrico Sintase Tipo I/biossíntese , Óxido Nítrico Sintase Tipo I/genética , Fragmentos de Peptídeos/farmacologia , RNA Mensageiro/biossíntese , Ratos , Ratos Sprague-Dawley
4.
J Econ Entomol ; 112(6): 2676-2685, 2019 12 09.
Artigo em Inglês | MEDLINE | ID: mdl-31504632

RESUMO

Neonicotinoids are used to protect citrus trees against pests. Dissipation and persistence of neonicotinoids in pollen and nectar of citrus trees after foliar applications and their potential exposure to pollinators have not been well characterized. Field studies were conducted using three orange and one mandarin varieties to compare the imidacloprid and thiamethoxam residue levels and their decline in pollen and nectar after treatments in pre-bloom close to flowering period and their persistence 1 yr after treatment. The possible risk to honeybees was assessed. In nectar, thiamethoxam and imidacloprid residues were between 61 and 99% lower than in pollen, depending on the citrus variety or/and the days after treatment when applied close to blooming. At the end of the flowering period, imidacloprid in pollen and nectar was not detected in the mandarin variety after treatment in pre-bloom, whereas for thiamethoxam, no residues were detected in nectar but 10 ng/g was detected in pollen. There were no quantifiable levels of residues for either neonicotinoids in pollen or nectar during the flowering period of the following year. Neonicotinoid residue levels and their decline in nectar and pollen in citrus depended on the timing of applications relative to flowering and on the citrus variety. The absence of neonicotinoid residues 1 yr out after foliar applications in all varieties assayed demonstrated that none of the neonicotinoids tested were persistent. The results could be different in other citrus varieties, and therefore, also the exposure assessment for managed pollinators.


Assuntos
Citrus , Inseticidas , Animais , Abelhas , Neonicotinoides , Nitrocompostos , Tiametoxam
5.
Biochim Biophys Acta Mol Basis Dis ; 1865(11): 165527, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31398465

RESUMO

Increasing evidence shows that the olfactory bulb is involved in blood pressure regulation in health and disease. Enhanced noradrenergic transmission in the olfactory bulb was reported in hypertension. Given that endothelins modulate catecholamines and are involved in the pathogenesis of hypertension, in the present study we sought to establish the role of the endothelin receptor type A on tyrosine hydroxylase, the rate limiting enzyme in catecholamine biosynthesis, in the olfactory bulb of DOCA-salt hypertensive rats. Sprague-Dawley male rats, randomly divided into Control and DOCA-Salt hypertensive groups, were used to assess endothelin receptors by Western blot and confocal microscopy, and their co-localization with tyrosine hydroxylase in the olfactory bulb. Blood pressure and heart rate as well as tyrosine hydroxylase expression and activity were assessed following BQ610 (ETA antagonist) applied to the brain. DOCA-Salt hypertensive rats showed enhanced ETA and decreased ETB expression. ETA co-localized with tyrosine hydroxylase positive neurons. Acute ETA blockade reduced blood pressure and heart rate and decreased the expression of total tyrosine hydroxylase and its phosphorylated forms. Furthermore, it also diminished mRNA tyrosine hydroxylase expression and accelerated the enzyme degradation through the proteasome pathway as shown by pretreatment with MG132, (20s proteasome inhibitor) intracerebroventricularly applied. Present findings support that the brain endothelinergic system plays a major role through ETA activation in the increase of catecholaminergic activity in the olfactory bulb of DOCA-Salt hypertensive rats. They provide rationale evidence that this telencephalic structure contributes in a direct or indirect way to the hemodynamic regulation in salt dependent hypertension.


Assuntos
Catecolaminas/metabolismo , Hipertensão/fisiopatologia , Bulbo Olfatório/fisiopatologia , Receptor de Endotelina A/metabolismo , Animais , Pressão Sanguínea , Acetato de Desoxicorticosterona/efeitos adversos , Hemodinâmica , Hipertensão/etiologia , Hipertensão/metabolismo , Masculino , Bulbo Olfatório/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor de Endotelina A/análise
6.
Talanta ; 204: 153-162, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31357277

RESUMO

In the last years, the honeybee population is facing growing threats such as expansion of pathogens, incorrect use of phytosanitary products and environmental contaminants, loss or fragmentation of habitat, invasive species and climate change. The citrus cropping by Integrated Pest Management (IPM) in Spain combines strategies to reduce pest populations preventing environmental problems and reducing levels of damage by using chemicals only when it is strictly necessary. The goal of this study is to develop a simple analytical method to evaluate pesticide residue levels in honeybees and corbicular pollen when honeybees are exposed to plant protection products (PPPs) used in integrated pest management citrus orchards. The proposed method is based in an ultrasound assisted extraction procedure followed by a dispersive solid phase extraction (d-SPE) clean-up with alumina and LC-MS/MS pesticides determination. The method was validated in samples of honeybee and corbicular pollen for 10 pesticides commonly used in citrus orchards under IPM. This procedure was compared with QuEChERS methodologies for these matrices. The developed method was applied to determine pesticides in both matrices in a two -year study in citrus orchards.


Assuntos
Abelhas/química , Citrus/química , Resíduos de Praguicidas/análise , Pólen/química , Animais , Cromatografia Líquida/métodos , Monitoramento Ambiental/métodos , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Ondas Ultrassônicas
7.
Int J Mol Sci ; 19(3)2018 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-29495426

RESUMO

Overactivity of the sympathetic nervous system and central endothelins (ETs) are involved in the development of hypertension. Besides the well-known brain structures involved in the regulation of blood pressure like the hypothalamus or locus coeruleus, evidence suggests that the olfactory bulb (OB) also modulates cardiovascular function. In the present study, we evaluated the interaction between the endothelinergic and catecholaminergic systems in the OB of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Following brain ET receptor type A (ETA) blockade by BQ610 (selective antagonist), transcriptional, traductional, and post-traductional changes in tyrosine hydroxylase (TH) were assessed in the OB of normotensive and DOCA-salt hypertensive rats. Time course variations in systolic blood pressure and heart rate were also registered. Results showed that ETA blockade dose dependently reduced blood pressure in hypertensive rats, but it did not change heart rate. It also prevented the increase in TH activity and expression (mRNA and protein) in the right OB of hypertensive animals. However, ETA blockade did not affect hemodynamics or TH in normotensive animals. Present results support that brain ETA are not involved in blood pressure regulation in normal rats, but they significantly contribute to chronic blood pressure elevation in hypertensive animals. Changes in TH activity and expression were observed in the right but not in the left OB, supporting functional asymmetry, in line with previous studies regarding cardiovascular regulation. Present findings provide further evidence on the role of ETs in the regulation of catecholaminergic activity and the contribution of the right OB to DOCA-salt hypertension.


Assuntos
Pressão Sanguínea/efeitos dos fármacos , Catecolaminas/metabolismo , Antagonistas do Receptor de Endotelina A/farmacologia , Hipertensão/etiologia , Hipertensão/metabolismo , Bulbo Olfatório/efeitos dos fármacos , Bulbo Olfatório/metabolismo , Receptor de Endotelina A/metabolismo , Animais , Catecolaminas/farmacologia , Acetato de Desoxicorticosterona/efeitos adversos , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Expressão Gênica , Frequência Cardíaca/efeitos dos fármacos , Hipertensão/fisiopatologia , Masculino , Fosforilação , Ratos , Tirosina 3-Mono-Oxigenase/genética , Tirosina 3-Mono-Oxigenase/metabolismo
9.
Exp Physiol ; 100(6): 617-27, 2015 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-25809871

RESUMO

NEW FINDINGS: What is the central question of this study? Does ex vivo administration of endothelin-1 and endothelin-3 regulate noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate-salt hypertensive rats compared with normotensive rats? What is the main finding and its importance? Endothelin-1 and endothelin-3 enhanced diverse mechanisms leading to increased noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate-salt hypertensive rats. Unveiling the role of brain endothelins in hypertension would probably favour the development of new therapeutic targets for the treatment of essential hypertension, which still represents a challenging disease with high mortality. Brain catecholamines participate in diverse biological functions regulated by the hypothalamus. We have previously reported that endothelin-1 and endothelin-3 (ET-1 and ET-3) modulate catecholaminergic activity in the anterior and posterior hypothalamus of normotensive rats. The aim of the present study was to evaluate the interaction between endothelins and noradrenergic transmission in the posterior hypothalamus of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. We assessed the effects of ET-1 and ET-3 on tyrosine hydroxylase activity and expression, neuronal noradrenaline (NA) release, neuronal NA transporter (NAT) activity and expression, monoamine oxidase activity and NA endogenous content and utilization (as a marker of turnover) in the posterior hypothalamus of DOCA-salt hypertensive rats. In addition, levels of ETA and ETB receptors were assayed in normotensive and hypertensive rats. Results showed that tyrosine hydroxylase activity and total and phosphorylated levels, NAT activity and content, NA release, monoamine oxidase activity and NA utilization were increased in DOCA-salt rats. Both ET-1 and ET-3 further enhanced all noradrenergic parameters except for total tyrosine hydroxylase level and NA endogenous content and utilization. The expression of ETA receptors was increased in the posterior hypothalamus of DOCA-salt rats, but ETB receptors showed no changes. These results show that ET-1 and ET-3 upregulate noradrenergic activity in the posterior hypothalamus of DOCA-salt hypertensive rats. Our findings suggest that the interaction between noradrenergic transmission and the endothelinergic system in the posterior hypothalamus may be involved in the development and/or maintenance of hypertension in this animal model.


Assuntos
Neurônios Adrenérgicos/efeitos dos fármacos , Acetato de Desoxicorticosterona , Endotelina-1/administração & dosagem , Endotelina-3/administração & dosagem , Hipertensão/metabolismo , Hipotálamo Posterior/efeitos dos fármacos , Norepinefrina/metabolismo , Cloreto de Sódio na Dieta , Transmissão Sináptica/efeitos dos fármacos , Neurônios Adrenérgicos/metabolismo , Animais , Pressão Sanguínea/efeitos dos fármacos , Modelos Animais de Doenças , Hipertensão/induzido quimicamente , Hipertensão/fisiopatologia , Hipotálamo Posterior/metabolismo , Hipotálamo Posterior/fisiopatologia , Masculino , Monoaminoxidase/metabolismo , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/metabolismo , Fosforilação , Ratos Sprague-Dawley , Receptor de Endotelina A/efeitos dos fármacos , Receptor de Endotelina A/metabolismo , Receptor de Endotelina B/efeitos dos fármacos , Receptor de Endotelina B/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo
10.
Vitam Horm ; 98: 371-405, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25817875

RESUMO

Neuronal norepinephrine (NE) uptake is a crucial step in noradrenergic neurotransmission that regulates NE concentration in the synaptic cleft. It is a key mechanism mediated by the NE transporter (NET) which takes the neurotransmitter into the presynaptic neuron terminal or the adrenal medulla chromaffin cell. The activity of NET is short and long terms modulated by phosphorylation mediated by protein kinases A, C, and G and calcium-calmodulin-dependent protein kinase, whereas the transporter availability at the cell surface is regulated by glycosylation. Several neuropeptides like angiotensins II, III, and 1-7, bradykinin, natriuretic peptides, as well as endothelins (ETs) regulate a wide variety of biological effects, including noradrenergic transmission and in particular neuronal NE uptake. Diverse reports, including studies from our laboratory, show that ETs differentially modulate the activity and expression of NET not only in normal conditions but also in diverse cardiovascular diseases such as congestive heart failure and hypertension. Current literature supports a key role for the interaction between ETs and NE in maintaining neurotransmission homeostasis and further suggests that this interaction may represent a potential therapeutic target for various diseases, particularly hypertension.


Assuntos
Transporte Biológico/fisiologia , Endotelinas/metabolismo , Proteínas da Membrana Plasmática de Transporte de Norepinefrina/metabolismo , Norepinefrina/metabolismo , Transdução de Sinais/fisiologia , Animais , Doenças Cardiovasculares/metabolismo , Homeostase/fisiologia , Humanos
11.
PLoS One ; 10(2): e0116597, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-25710381

RESUMO

Aberrations in the ubiquitin-proteasome system (UPS) are implicated in the pathogenesis of various diseases. Tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamines biosynthesis, is involved in hypertension development. In this study we investigated whether UPS regulated TH turnover in PC12 cells and hypothalamic and brainstem neurons from spontaneously hypertensive rats (SHR) and whether this system was impaired in hypertension. PC12 cells were exposed to proteasome or lysosome inhibitors and TH protein level evaluated by Western blot. Lactacystin, a proteasome inhibitor, induced an increase of 86 ± 15% in TH levels after 30 min of incubation, then it started to decrease up to 6 h to reach control levels and finally it rose up to 35.2 ± 8.5% after 24 h. Bafilomycin, a lysosome inhibitor, did not alter TH protein levels during short times, but it increased TH by 92 ± 22% above basal after 6 h treatment. Before degradation proteasome substrates are labeled by conjugation with ubiquitin. Efficacy of proteasome inhibition on TH turnover was evidenced by accumulation of ubiquitinylated TH after 30 min. Further, the inhibition of proteasome increased the quantity of TH phosphorylated at Ser40, which is essential for TH activity, by 2.7 ± 0.3 fold above basal. TH protein level was upregulated in neurons from hypothalami and brainstem of SHR when the proteasome was inhibited during 30 min, supporting that neuronal TH is also short-term regulated by the proteasome. Since the increased TH levels reported in hypertension may result from proteasome dysfunction, we evaluate proteasome activity. Proteasome activity was significantly reduced by 67 ± 4% in hypothalamic and brainstem neurons from SHR while its protein levels did not change. Present findings show that TH is regulated by the UPS. The impairment in proteasome activity observed in SHR neurons may be one of the causes of the increased TH protein levels reported in hypertension.


Assuntos
Tronco Encefálico/metabolismo , Hipertensão/metabolismo , Hipotálamo/metabolismo , Neurônios/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Ubiquitina/metabolismo , Acetilcisteína/análogos & derivados , Acetilcisteína/farmacologia , Animais , Tronco Encefálico/citologia , Hipotálamo/citologia , Masculino , Células PC12 , Inibidores de Proteassoma/farmacologia , Ratos , Ratos Endogâmicos SHR , Ratos Wistar , Tirosina 3-Mono-Oxigenase/genética
12.
Anal Chem ; 87(2): 1018-25, 2015 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-25495653

RESUMO

This manuscript reports a new pesticide residue analysis method employing a microflow-liquid chromatography system coupled to a triple quadrupole mass spectrometer (microflow-LC-ESI-QqQ-MS). This uses an electrospray ionization source with a narrow tip emitter to generate smaller droplets. A validation study was undertaken to establish performance characteristics for this new approach on 90 pesticide residues, including their degradation products, in three commodities (tomato, pepper, and orange). The significant benefits of the microflow-LC-MS/MS-based method were a high sensitivity gain and a notable reduction in matrix effects delivered by a dilution of the sample (up to 30-fold); this is as a result of competition reduction between the matrix compounds and analytes for charge during ionization. Overall robustness and a capability to withstand long analytical runs using the microflow-LC-MS system have been demonstrated (for 100 consecutive injections without any maintenance being required). Quality controls based on the results of internal standards added at the samples' extraction, dilution, and injection steps were also satisfactory. The LOQ values were mostly 5 µg kg(-1) for almost all pesticide residues. Other benefits were a substantial reduction in solvent usage and waste disposal as well as a decrease in the run-time. The method was successfully applied in the routine analysis of 50 fruit and vegetable samples labeled as organically produced.


Assuntos
Cromatografia Líquida/métodos , Resíduos de Praguicidas/análise , Extração em Fase Sólida/métodos , Solventes/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Capsicum/química , Citrus sinensis/química , Solanum lycopersicum/química , Sensibilidade e Especificidade
13.
Neurochem Res ; 38(10): 2063-71, 2013 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-23888389

RESUMO

The ablation of olfactory bulb induces critical changes in dopamine, and monoamine oxidase activity in the brain stem. Growing evidence supports the participation of this telencephalic region in the regulation blood pressure and cardiovascular activity but little is known about its contribution to hypertension. We have previously reported that in the olfactory bulb of normotensive rats endothelins enhance noradrenergic activity by increasing tyrosine hydroxylase activity and norepinephrine release. In the present study we sought to establish the status of noradrenergic activity in the olfactory bulb of deoxycorticosterone acetate (DOCA)-salt hypertensive rats. Different steps in norepinephrine transmission including tyrosine hydroxylase activity, neuronal norepinephrine release and uptake were assessed in the left and right olfactory bulb of DOCA-salt hypertensive rats. Increased tyrosine hydroxylase activity, and decreased neuronal norepinephrine uptake were observed in the olfactory bulb of DOCA-salt hypertensive rats. Furthermore the expression of tyrosine hydroxylase and its phosphorylated forms were also augmented. Intriguingly, asymmetrical responses between the right and left olfactory bulb of normotensive and hypertensive rats were observed. Neuronal norepinephrine release was increased in the right but not in the left olfactory bulb of DOCA-salt hypertensive rats, whereas non asymmetrical differences were observed in normotensive animals. Present findings indicate that the olfactory bulb of hypertensive rats show an asymmetrical increase in norepinephrine activity. The observed changes in noradrenergic transmission may likely contribute to the onset and/or progression of hypertension in this animal model.


Assuntos
Hipertensão/fisiopatologia , Norepinefrina/metabolismo , Bulbo Olfatório/fisiopatologia , Animais , Acetato de Desoxicorticosterona , Lateralidade Funcional , Hipertensão/induzido quimicamente , Masculino , Bulbo Olfatório/patologia , Ratos , Ratos Sprague-Dawley , Cloreto de Sódio na Dieta , Transmissão Sináptica/fisiologia , Tirosina 3-Mono-Oxigenase/metabolismo
14.
Neurochem Int ; 62(4): 389-98, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23357475

RESUMO

Endothelins (ETs) are widely expressed in the olfactory bulb (OB) and other brain areas where they function as neuropeptides. In a previous study we reported that in the OB ET-1 and ET-3 participate in the long-term regulation of tyrosine hydroxylase (TH), the key enzyme in catecholamine biosynthesis. ETs stimulate TH activity by increasing total and phosphorylated enzyme levels as well as its mRNA. ET-1 response is mediated by a super high affinity ETA receptor coupled to adenylyl cyclase/protein kinase A and Ca(2+)/calmodulin-dependent protein kinase II (CaMK-II) activation whereas that of ET-3 through an atypical receptor coupled not only to these signaling pathways but also to phospholipase C (PLC)/protein kinase C pathway. Given the participation of PLC and CaMKII in the regulation of TH by ETs in the OB we sought to establish the contribution of calcium to ETs response. Present findings show that calcium released from ryanodine-sensitive channels and extracellular calcium were necessary to stimulate TH by ETs through CaMK-II. On the other hand, intracellular calcium released by the endoplasmic reticulum partially mediated ETs-evoked increase in TH mRNA but calcium influx and CaMK-II inhibition abolished the response. However calcium mechanisms were not involved in ETs-evoked increase in TH protein content. Present findings support that different sources of calcium contribute to the long-term modulation of TH activity and expression mediated by ETs in the rat OB.


Assuntos
Cálcio/metabolismo , Endotelinas/fisiologia , Bulbo Olfatório/enzimologia , Tirosina 3-Mono-Oxigenase/metabolismo , Animais , Sequência de Bases , Primers do DNA , Masculino , RNA Mensageiro/genética , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Tirosina 3-Mono-Oxigenase/genética
15.
Thromb Haemost ; 107(1): 37-43, 2012 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22116496

RESUMO

Long-term therapy with low-molecular-weight heparin (LMWH) is the treatment of choice for cancer patients with venous thromboembolism (VTE). However, the ideal doses of LMWH have not been thoroughly studied. We used the RIETE Registry data to assess the influence of the daily LMWH dosage on outcome during the first three months after VTE. We used propensity score-matching to compare patients who received <150 vs. those receiving ≥150 UI/kg/day LMWH. Up to July 2010, 3,222 cancer patients with VTE received long-term therapy with fixed doses of LMWH. Of these, 1,472 (46%) received <150 IU/kg/day (mean, 112 ± 28), and 1,750 received ≥150 IU/kg/day (mean, 184 ± 32). Results of the propensity score matching involved 1269 matched pairs. During follow-up, the incidence of pulmonary embolism (PE) recurrences was similar (1.2% vs. 1.9%), but patients receiving <150 IU/kg/day LMWH had a lower incidence of fatal PE than those treated with ≥150 IU/kg/day (0.2% vs. 1.0%; p=0.004). Multivariate analysis confirmed that patients receiving <150 IU/kg/day LMWH had a lower risk for fatal PE (odds ratio [OR]: 0.2; 95% confidence interval [CI]: 0.06-0.8) and for major bleeding (OR: 0.6; 95% CI: 0.3-1.0) than those treated with ≥150 IU/kg/day. In real life, one in every two cancer patients with VTE received lower doses of LMWH than those used in randomised trials, with large variations from patient to patient. Unexpectedly, patients treated with <150 IU/kg/day LMWH had fewer fatal PE cases and fewer major bleeding events than those receiving ≥150 IU/kg/day LMWH. This finding, however, should be validated in prospective clinical trials.


Assuntos
Heparina de Baixo Peso Molecular/uso terapêutico , Neoplasias/complicações , Neoplasias/tratamento farmacológico , Embolia Pulmonar/complicações , Embolia Pulmonar/prevenção & controle , Tromboembolia Venosa/complicações , Tromboembolia Venosa/tratamento farmacológico , Idoso , Algoritmos , Esquema de Medicação , Feminino , Hemorragia , Heparina de Baixo Peso Molecular/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Recidiva , Sistema de Registros , Resultado do Tratamento
16.
Neurochem Int ; 58(2): 196-205, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21129429

RESUMO

The olfactory bulbs play a relevant role in the interaction between the animal and its environment. The existence of endothelin-1 and -3 in the rat olfactory bulbs suggests their role in the control of diverse functions regulated at this level. Tyrosine hydroxylase, a crucial enzyme in catecholamine biosynthesis, is tightly regulated by short- and long-term mechanisms. We have previously reported that in the olfactory bulbs endothelins participate in the short-term tyrosine hydroxylase regulation involving complex mechanisms. In the present work we studied the effect of long-term stimulation by endothelins on tyrosine hydroxylase in the rat olfactory bulbs. Our findings show that endothelin-1 and -3 modulated catecholaminergic transmission by increasing enzymatic activity. However, these peptides acted through different receptors and intracellular pathways. Endothelin-1 enhanced tyrosine hydroxylase activity through a super high affinity ET(A) receptor and cAMP/PKA and CaMK-II pathways, whereas, endothelin-3 through a super high affinity atypical receptor coupled to cAMP/PKA, PLC/PKC and CaMK-II pathways. Endothelins also increased tyrosine hydroxylase mRNA and the enzyme total level as well as the phosphorylation of Ser 19, 31 and 40 sites. Furthermore, both peptides stimulated dopamine turnover and reduced its endogenous content. These findings support that endothelins are involved in the long-term regulation of tyrosine hydroxylase, leading to an increase in the catecholaminergic activity which might be implicated in the development and/or maintenance of diverse pathologies involving the olfactory bulbs.


Assuntos
Catecolaminas/biossíntese , Endotelinas/metabolismo , Bulbo Olfatório/metabolismo , Tirosina 3-Mono-Oxigenase/metabolismo , Animais , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/metabolismo , Domínio Catalítico/efeitos dos fármacos , Domínio Catalítico/fisiologia , AMP Cíclico/metabolismo , Endotelina-1/metabolismo , Endotelina-1/farmacologia , Endotelina-3/metabolismo , Endotelina-3/farmacologia , Endotelinas/farmacologia , Ativação Enzimática/efeitos dos fármacos , Ativação Enzimática/fisiologia , Masculino , Transtornos do Olfato/metabolismo , Transtornos do Olfato/fisiopatologia , Bulbo Olfatório/efeitos dos fármacos , Fosforilação/efeitos dos fármacos , Fosforilação/fisiologia , RNA Mensageiro/efeitos dos fármacos , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptor de Endotelina A/agonistas , Receptor de Endotelina A/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Tempo , Fatores de Tempo , Fosfolipases Tipo C/metabolismo
17.
Neuroepidemiology ; 35(2): 101-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20551696

RESUMO

BACKGROUND: The purpose of this study was to analyze and determine the prevalence and clinical characteristics of hospitalized dementia patients compared with nondemented patients. METHODS: We examined hospital discharge database records dated 1998-2003 from public hospitals in Andalusia, Spain. We used ICD-9-CM codes to identify patients with dementia. The variables examined included age, length of stay, discharge diagnosis, diagnostic-related groups, and mortality of both dementia and nondementia patients over 65 years of age. RESULTS: A diagnosis of dementia was documented for 40,482 cases. The prevalence of dementia increased from 3.43% to 4.64% between 1998 and 2003 and was higher among older patients and women. Dementia was the reason for admission in 5.6% of cases. Medical reasons constituted 82.4% of admittances. Dementia patients had hip surgery more frequently than patients without dementia, and other procedures (orthopedic surgery, cataracts, or hernia repair) were less frequent (p < 0.001). The mean duration of the hospital stay was longer (13.4 vs. 10.7 days) and the intra-hospital mortality rate was greater (19.3% vs. 8.7%) for patients with dementia compared to those without dementia. Dementia was an independent predictor of mortality (OR 1.77; 95% CI 1.72-1.82). CONCLUSIONS: Dementia is increasing among hospitalized patients. Dementia patients have different reasons for hospitalization and higher mortality. It is necessary to identify these differences and to improve the hospital care of dementia patients.


Assuntos
Demência/epidemiologia , Hospitalização/estatística & dados numéricos , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Doenças Cardiovasculares/complicações , Doenças Cardiovasculares/epidemiologia , Comorbidade , Bases de Dados Factuais , Demência/complicações , Grupos Diagnósticos Relacionados , Feminino , Mortalidade Hospitalar , Unidades Hospitalares/estatística & dados numéricos , Humanos , Classificação Internacional de Doenças , Tempo de Internação , Masculino , Procedimentos Ortopédicos/estatística & dados numéricos , Alta do Paciente , Espanha/epidemiologia , Centro Cirúrgico Hospitalar/estatística & dados numéricos
18.
Chest ; 133(1): 143-8, 2008 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17925416

RESUMO

BACKGROUND: There is little information on the clinical outcome of patients with upper-extremity deep vein thrombosis (DVT). METHODS: RIETE is an ongoing registry of consecutive patients with objectively confirmed, symptomatic, acute DVT or pulmonary embolism (PE). In this analysis, we analyzed the demographic characteristics, treatment, and 3-month outcome of all patients with DVT in the arm. RESULTS: Of the 11,564 DVT patients enrolled, 512 patients (4.4%) had arm DVT. They presented less often with clinically overt PE (9.0% vs 29%; odds ratio, 0.24; 95% confidence interval [CI], 0.18 to 0.33) than those with lower-limb DVT, but their 3-month outcome was similar. Of the 512 patients with arm DVT, 196 patients (38%) had cancer and 228 patients (45%) had catheter-related DVT. During follow-up, those with cancer DVT had an increased incidence of major bleeding (4.1% vs 0.9%; odds ratio, 4.4; 95% CI, 1.2 to 21), recurrent venous thromboembolism (6.1% vs 2.8%; odds ratio, 2.2; 95% CI, 0.91 to 5.6; p = 0.04), and death (22% vs 3.5%; odds ratio, 7.8; 95% CI, 4.0 to 16). Thirty patients had the composite event of recurrent DVT, symptomatic PE, or major bleeding. They were significantly older, more often had cancer, and presented more frequently with symptomatic PE on hospital admission. On multivariate analysis, only cancer patients with arm DVT had an increased risk for the composite event (odds ratio, 3.0; 95% CI, 1.4 to 6.4). CONCLUSIONS: At presentation, patients with arm DVT have less often clinically overt PE than those with lower-limb DVT, but their 3-month outcome is similar. Among patients with arm DVT, those with cancer have the worse outcome.


Assuntos
Braço , Trombose Venosa/terapia , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Sistema de Registros , Resultado do Tratamento
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