Molecular and functional characterization of an octopamine receptor from honeybee (Apis mellifera) brain

Biogenic amines and their receptors regulate and modulate many physiological and behavioural processes in animals. In vertebrates, octopamine is only found in trace amounts and its function as a true neurotransmitter is unclear. In protostomes, however, octopamine can act as neurotransmitter, neuromodulator and neurohormone. In the honeybee, octopamine acts as a neuromodulator and is involved in learning and memory formation. The identification of potential octopamine receptors is decisive for an understanding of the cellular pathways involved in mediating the effects of octopamine. Here we report the cloning and functional characterization of the first octopamine receptor from the honeybee, Apis mellifera . The gene was isolated from a brain-specific cDNA library. It encodes a protein most closely related to octopamine receptors from Drosophila melanogaster and Lymnea stagnalis . Signalling properties of the cloned receptor were studied in transiently transfected human embryonic kidney (HEK) 293 cells. Nanomolar to micromolar concentrations of octopamine induced oscillatory increases in the intracellular Ca2+ concentration. In contrast to octopamine, tyramine only elicited Ca2+ responses at micromolar concentrations. The gene is abundantly expressed in many somata of the honeybee brain, suggesting that this octopamine receptor is involved in the processing of sensory inputs, antennal motor outputs and higher-order brain functions.

Autosomal dominant hypocalcemia: A novel activating mutation (E604K) in the cysteine-rich domain of the calcium-sensing receptor

We report a novel activating mutation (E604K) of the calcium-sensing receptor in a family with autosomal dominant hypocalcemia. Whereas all affected individuals exhibited marked hypocalcemia, some cases with untreated hypocalcemia exhibited seizures in infancy, whereas others were largely asymptomatic from birth into adulthood. The missense mutation E604K (G2182A, GenBank accession no. U20759), which affects an amino acid residue in the C terminus of the cysteine-rich domain of the extracellular head, co-segregated with hypocalcemia in all seven individuals for whom DNA was available. Two unaffected, normocalcemic members of the family did not exhibit the mutation. The molecular impact of the mutation on two key components of the signaling response was assessed in HEK-293 cells transiently transfected with cDNA corresponding to either the wild-type calcium-sensing receptor or the E604K mutation derived by site-directed mutagenesis. There was a significant leftward shift in the concentration response curves for the effects of extracellular Ca2+ on both intracellular Ca2+ mobilization (determined by aequorin luminescence) and MAPK activity (determined by luciferase expression). The C terminus of the cysteine-rich domain of the extracellular head may normally act to suppress receptor activity in the presence of low extracellular Ca2+ concentrations.

A comparison of two methods for the calculation of accumulated oxygen deficit

The aim of this study was to compare accumulated oxygen deficit data derived using two different exercise protocols with the aim of producing a less time-consuming test specifically for use with athletes. Six road and four track male endurance cyclists performed two series of cycle ergometer tests. The first series involved five 10 min sub-maximal cycle exercise bouts, a (V) over dotO(2peak) test and a 115% (V) over dotO(2peak) test. Data from these tests were used to estimate the accumulated oxygen deficit according to the calculations of Medbo et al. (1988). In the second series of tests, participants performed a 15 min incremental cycle ergometer test followed, 2 min later, by a 2 min variable resistance test in which they completed as much work as possible while pedalling at a constant rate. Analysis revealed that the accumulated oxygen deficit calculated from the first series of tests was higher (P< 0.02) than that calculated from the second series: 52.3 +/- 11.7 and 43.9 +/- 6.4 ml . kg(-1), respectively (mean +/- s). Other significant differences between the two protocols were observed for (V) over dot O-2peak, total work and maximal heart rate; all were higher during the modified protocol (P

Ventricular performance and Na+-K+ ATPase activity are reduced early and late after myocardial infarction in rats

Myocardial infarction leads to compensatory ventricular remodeling. Disturbances in myocardial contractility depend on the active transport of Ca2+ and Na+, which are regulated by Na+-K+ ATPase. Inappropriate regulation of Na+-K+ ATPase activity leads to excessive loss of K+ and gain of Na+ by the cell. We determined the participation of Na+-K+ ATPase in ventricular performance early and late after myocardial infarction. Wistar rats (8-10 per group) underwent left coronary artery ligation (infarcted, Inf) or sham-operation (Sham). Ventricular performance was measured at 3 and 30 days after surgery using the Langendorff technique. Left ventricular systolic pressure was obtained under different ventricular diastolic pressures and increased extracellular Ca2+ concentrations (Ca2+e) and after low and high ouabain concentrations. The baseline coronary perfusion pressure increased 3 days after myocardial infarction and normalized by 30 days (Sham 3 = 88 �� 6; Inf 3 = 130 �� 9; Inf 30 = 92 �� 7 mmHg; P < 0.05). The inotropic response to Ca2+e and ouabain was reduced at 3 and 30 days after myocardial infarction (Ca2+ = 1.25 mM; Sham 3 = 70 �� 3; Inf 3 = 45 �� 2; Inf 30 = 29 �� 3 mmHg; P < 0.05), while the Frank-Starling mechanism was preserved. At 3 and 30 days after myocardial infarction, ventricular Na+-K+ ATPase activity and contractility were reduced. This Na+-K+ ATPase hypoactivity may modify the Na+, K+ and Ca2+ transport across the sarcolemma resulting in ventricular dysfunction.

Lead reduces tension development and the myosin ATPase activity of the rat right ventricular myocardium

Lead (Pb2+) poisoning causes hypertension, but little is known regarding its acute effects on cardiac contractility. To evaluate these effects, force was measured in right ventricular strips that were contracting isometrically in 45 male Wistar rats (250-300 g) before and after the addition of increasing concentrations of lead acetate (3, 7, 10, 30, 70, 100, and 300 ��M) to the bath. Changes in rate of stimulation (0.1-1.5 Hz), relative potentiation after pauses of 15, 30, and 60 s, effect of Ca2+ concentration (0.62, 1.25, and 2.5 mM), and the effect of isoproterenol (20 ng/mL) were determined before and after the addition of 100 ��M Pb2+. Effects on contractile proteins were evaluated after caffeine treatment using tetanic stimulation (10 Hz) and measuring the activity of the myosin ATPase. Pb2+ produced concentration-dependent force reduction, significant at concentrations greater than 30 ��M. The force developed in response to increasing rates of stimulation became smaller at 0.5 and 0.8 Hz. Relative potentiation increased after 100 ��M Pb2+ treatment. Extracellular Ca2+ increment and isoproterenol administration increased force development but after 100 ��M Pb2+ treatment the force was significantly reduced suggesting an effect of the metal on the sarcolemmal Ca2+ influx. Concentration of 100 ��M Pb2+ also reduced the peak and plateau force of tetanic contractions and reduced the activity of the myosin ATPase. Results showed that acute Pb2+ administration, although not affecting the sarcoplasmic reticulum activity, produces a concentration-dependent negative inotropic effect and reduces myosin ATPase activity. Results suggest that acute lead administration reduced myocardial contractility by reducing sarcolemmal calcium influx and the myosin ATPase activity. These results also suggest that lead exposure is hazardous and has toxicological consequences affecting cardiac muscle.

Eucalyptol, an essential oil, reduces contractile activity in rat cardiac muscle

Eucalyptol is an essential oil that relaxes bronchial and vascular smooth muscle although its direct actions on isolated myocardium have not been reported. We investigated a putative negative inotropic effect of the oil on left ventricular papillary muscles from male Wistar rats weighing 250 to 300 g, as well as its effects on isometric force, rate of force development, time parameters, post-rest potentiation, positive inotropic interventions produced by Ca2+ and isoproterenol, and on tetanic tension. The effects of 0.3 mM eucalyptol on myosin ATPase activity were also investigated. Eucalyptol (0.003 to 0.3 mM) reduced isometric tension, the rate of force development and time parameters. The oil reduced the force developed by steady-state contractions (50% at 0.3 mM) but did not alter sarcoplasmic reticulum function or post-rest contractions and produced a progressive increase in relative potentiation. Increased extracellular Ca2+ concentration (0.62 to 5 mM) and isoproterenol (20 nM) administration counteracted the negative inotropic effects of the oil. The activity of the contractile machinery evaluated by tetanic force development was reduced by 30 to 50% but myosin ATPase activity was not affected by eucalyptol (0.3 mM), supporting the idea of a reduction of sarcolemmal Ca2+ influx. The present results suggest that eucalyptol depresses force development, probably acting as a calcium channel blocker.

Reactivity of the isolated perfused rat tail vascular bed

Isolated segments of the perfused rat tail artery display a high basal tone when compared to other isolated arteries such as the mesenteric and are suitable for the assay of vasopressor agents. However, the perfusion of this artery in the entire tail has not yet been used for functional studies. The main purpose of the present study was to identify some aspects of the vascular reactivity of the rat tail vascular bed and validate this method to measure vascular reactivity. The tail severed from the body was perfused with Krebs solution containing different Ca2+ concentrations at different flow rates. Rats were anesthetized with sodium pentobarbital (65 mg/kg) and heparinized (500 U). The tail artery was dissected near the tail insertion, cannulated and perfused with Krebs solution plus 30 ��M EDTA at 36oC and 2.5 ml/min and the procedures were started after equilibration of the perfusion pressure. In the first group a dose-response curve to phenylephrine (PE) (0.5, 1, 2 and 5 ��g, bolus injection) was obtained at different flow rates (1.5, 2.5 and 3.5 ml/min). The mean perfusion pressure increased with flow as well as PE vasopressor responses. In a second group the flow was changed (1.5, 2, 2.5, 3 and 3.5 ml/min) at different Ca2+ concentrations (0.62, 1.25, 2.5 and 3.75 mM) in the Krebs solution. Increasing Ca2+ concentrations did not alter the flow-pressure relationship. In the third group a similar protocol was performed but the rat tail vascular bed was perfused with Krebs solution containing PE (0.1 ��g/ml). There was an enhancement of the effect of PE with increasing external Ca2+ and flow. PE vasopressor responses increased after endothelial damage with air and CHAPS, suggesting an endothelial modulation of the tone of the rat tail vascular bed. These experiments validate the perfusion of the rat tail vascular bed as a method to investigate vascular reactivity.

Effects of ouabain on vascular reactivity

Ouabain is an endogenous substance occurring in the plasma in the nanomolar range, that has been proposed to increase vascular resistance and induce hypertension. This substance acts on the a-subunit of Na+,K+-ATPase inhibiting the Na+-pump activity. In the vascular smooth muscle this effect leads to intracellular Na+ accumulation that reduces the activity of the Na+/Ca2+ exchanger and to an increased vascular tone. It was also suggested that circulating ouabain, even in the nanomolar range, sensitizes the vascular smooth muscle to vasopressor substances. We tested the latter hypothesis by studying the effects of ouabain in the micromolar and nanomolar range on phenylephrine (PE)-evoked pressor responses. The experiments were performed in normotensive and hypertensive rats in vivo, under anesthesia, and in perfused rat tail vascular beds. The results showed that ouabain pretreatment increased the vasopressor responses to PE in vitro and in vivo. This sensitization after ouabain treatment was also observed in hypertensive animals which presented an enhanced vasopressor response to PE in comparison to normotensive animals. It is suggested that ouabain at nanomolar concentrations can sensitize vascular smooth muscle to vasopressor stimuli possibly contributing to increased tone in hypertension.

Indicadores de qualidade do solo e determina����o de n��veis de degrada����o de pastagens

A utiliza����o do solo no Brasil foi realizada de forma explorat��ria, com a convers��o de sistemas naturais em sistemas agr��colas extrativistas. Grande parte das ��reas de sistemas naturais deu lugar ��s ��reas de cultivo, posteriormente sucedidas por pastagens, encontrando-se boa parte em elevado est��gio de degrada����o. Diante do exposto, o presente trabalho tem como objetivo avaliar a sensibilidade de alguns atributos f��sicos, qu��micos, compartimentos da mat��ria org��nica e determina����es de campo como indicadores de qualidade do solo estabelecendo rela����es entre os mesmos. O estudo foi desenvolvido no munic��pio de Governador Valadares-MG, para tal foram escolhidos n��veis de pastagens progressivamente degradadas observadas visualmente (pastagem 1, pastagem 2, pastagem 3 e pastagem 4), duas ��reas de capoeira em est��gios de regenera����o natural (capoeira 1 e capoeira 2) e mata (refer��ncia). O solo em estudo foi um Argissolo Vermelho, textura argilosa. As determina����es dos indicadores f��sicos, qu��micos e compartimentos da mat��ria org��nica foram realizadas em quatro profundidades (0-5, 5-10, 10-20 e 20-40 cm). Foram realizadas tamb��m determina����es de campo, todos os atributos foram determinados no ter��o m��dio de uma pedoforma convexa, em dois per��odos, chuvoso e seco. Atrav��s dos atributos do solo utilizados como indicadores do solo, foi poss��vel separar dois n��veis de pastagens degradadas, baixa degrada����o (pastagem 1 e pastagem 2) e elevada degrada����o (pastagem 3 e pastagem 4). A melhor qualidade do solo foi observada na ��rea de mata. Entre os atributos do solo utilizados como indicadores de qualidade do solo os mais sens��veis aos n��veis de pastagens degradadas s��o os atributos qu��micos pH, Ca2+, Mg2+, Al3+, H+Al, satura����o por bases (V), satura����o por alum��nio (m), seguidos pelos atributos f��sicos macroporosidade e porosidade total. Os compartimentos da mat��ria org��nica do solo, mat��ria org��nica particulada (MOP), mat��ria org��nica leve (MOL) e carbono sol��vel em ��gua (CSA) utilizados como indicadores de qualidade do solo s��o eficientes em diferenciar a qualidade do solo nas convers��es de sistema, mata/pastagens e pastagens/capoeiras, n��o sendo sens��vel aos n��veis de pastagens degradadas, o que sugere estudos futuros utilizado compartimentos mais sens��veis a pequenas varia����es. As determina����es de campo espessura do horizonte ���A���, profundidade do sistema radicular e taxa de cobertura do solo s��o sens��veis aos n��veis de pastagens degradadas, e apresentam uma boa correla����o com os indicadores de laborat��rio macroporosidade (Ma), mat��ria org��nica particulada (MOP), satura����o por bases (V), satura����o por alum��nio (m) sugerindo assim a utiliza����o dessas determina����es como indicadores de qualidade do solo em pastagens degradadas, para o solo e a regi��o estudados.

Cobertura permanente de solo com leguminosas herb��ceas perenes no cultivo de bananeiras no m��dio Vale do Jequitinhonha

A regi��o da Caatinga �� caracterizada pelas altas temperaturas durante o ano e m�� distribui����o das chuvas. Em virtude desses fatores de clima regional, tem-se a necessidade de ado����o por pr��ticas que elevem �� efici��ncia e sustentabilidade agr��cola local. Assim, objetivou-se avaliar a aptid��o de leguminosas herb��ceas perenes como cobertura permanente de solo no cultivo de bananeira. Foram conduzidos tr��s experimentos, para avalia����o das leguminosas, utilizou-se um delineamento experimental em blocos casualizados, com quatro repeti����es, em esquema de parcelas subdivididas no espa��o e para algumas vari��veis, sub-subdividida no tempo, sendo: Fator ���A��� os dois diferentes ambientes de plantio: munic��pios de Itaobim/MG e Virgem da Lapa/MG; Fator ���B���, nas subparcelas, dois manejos de cobertura do solo e para algumas vari��veis, tr��s manejos, constitu��dos pelas leguminosas: cudzu tropical (Pueraria phaseoloides) calopog��nio (Calopogonium mucunoides) e solo descoberto (solo capinado); Fator ���C��� ��pocas de coleta de dados. Para avalia����o das bananeiras, foram dois experimentos em blocos casualizados, com quatro repeti����es, em esquema de parcelas sudivididas no espa��o, sendo: nas parcelas, fator ���A��� constitu��do por tr��s manejos de cobertura do solo, pelas leguminosas: cudzu tropical e o calopog��nio, e solo descoberto (solo capinado); fator ���B���, nas subparcelas, plantas de bananeiras em tr��s idades morfofisiol��gicas (diferentes ciclos e tamanhos); Para algumas vari��veis que foram submetidas a coletas peri��dicas, utilizou-se o esquema de parcelas subsubdivididas no tempo, acrescentando-se o fator ���C���, datas das coletas nas sub-subparcelas, tendo como refer��ncia os dias ap��s semeadura (DAS) das leguminosas. Foram avaliadas as seguintes vari��veis: taxa de cobertura do solo; potencial de deposi����o de folhas e a ciclagem de nutrientes; capacidade de inibi����o da vegeta����o espont��nea; conserva����o da temperatura e promo����o da reten����o de umidade do solo. Tamb��m foi avaliado o crescimento vegetativo e produtividade das bananeiras. Como resultados principais, notou-se que as leguminosas proporcionaram eficiente cobertura do solo, o calopog��nio apresentou o maior ac��mulo de N, P, K, e Ca, via deposi����o de material senescente, tal como maior inibi����o das plantas espont��neas nos pomares de bananeiras. Essa cobertura tamb��m promoveu uma eficiente redu����o da temperatura do solo, possibilitando menor varia����o t��rmica nas camadas de maior concentra����o radicular da bananeira, e consequentemente, obtendo maior ac��mulo de umidade no solo. As bananeiras cultivadas sobre coberturas vivas de solo apresentaram aumento gradativo no crescimento e peso de cacho. Os resultados refor��am o potencial uso dessas esp��cies na fruticultura, principalmente em regi��es de severas restri����es h��dricas, como forma de aduba����o e otimiza����o de diversos processos biol��gicos em seu ambiente de cultivo.

Phytomass production and nutrient accumulation by green manure species

Green manuring is recognized as a viable alternative to improve nutrient cycling in soils. The aim of this study was to evaluate the phytomass production and nutrient accumulation in shoots of the summer green manures jack bean &#91;Canavalia ensiformis (L.) DC.&#93;, dwarf pigeon pea (Cajanus cajanvar var. Flavus DC.), dwarf mucuna &#91;Mucuna deeringiana (Bort) Merr&#93; and sunn hemp (Crotalaria juncea L.), under nitrogen fertilization and/or inoculation with N-fixing bacteria. A split plot design was arranged with the four Fabaceae species as main plots and nitrogen fertilization (with and without) and inoculation with diazotrophic bacteria (with and without) as the subplots, in a 2�� factorial. The experiment was arranged as a randomized complete block design with four replications. In the conditions of this trial, the sunn hemp had the highest production of shoot phytomass (12.4 Mg ha-1) and nutrient accumulation, while the dwarf mucuna had the lowest production of shoot phytomass (3.9 Mg ha-1) and nutrient accumulation. The results showed no effect of nitrogen fertilization or inoculation with N-fixing bacteria on the production of shoot phytomass and nutrient accumulation, except for inoculation without nitrogen fertilization, resulting in greater P accumulation (p <0.05) in the sunn hemp and greater Zn and Mn accumulation in the dwarf mucuna. These findings indicate that N fertilization or inoculation with N2-fixing bacteria for Fabaceae are low efficiency practices in the edaphoclimatic conditions of this study.

Cristaliza����o de Biomateriais Vitrocer��micos e Mineraliza����o em Meio Fisiol��gico Simulado

We propose new theoretical models, which generalize the classical Avrami-Nakamura models. These models are suitable to describe the kinetics of nucleation and growth in transient regime, and/or with overlapping of nucleation and growth. Simulations and predictions were performed for lithium disilicate based on data reported in the literature. One re-examined the limitations of the models currently used to interpret DTA or DSC results, and to extract the relevant kinetic parameters. Glasses and glass-ceramics with molar formulation 0.45SiO2? (0.45-x)MgO?xK2O?0.1(3CaO.P2O5) (0?x?0.090) were prepared, crystallized and studied as potential materials for biomedical applications. Substitution of K+ for Mg2+ were used to prevent devritification on cooling, to adjust the kinetics of crystallization and to modify the in vitro behaviour of resulting biomaterials. The crystallization of the glass frits was studied by DTA, XRD and SEM. Exothermic peaks were detected corresponding to bulk crystallization of whitlockite-type phosphate, Ca9MgK(PO4)7, at approximately 900��C, and surface crystallization of a predominant forsterite phase (Mg2SiO4) at higher temperatures. XRD also revealed the presence of diopside (CaMgSi2O6 in some samples. The predominant microstructure of the phosphate phase is of the plate-type, seemingly crystallizing by a 2-dimensional growth mechanism. Impedance spectroscopy revealed significant changes in electrical behaviour, associated to crystallization of the phosphate phase. This showed that electrical measurements can be used to study the kinetics of crystallization for cases when DTA or DSC experiments reveal limitations, and to extract estimates of relevant parameters from the dependence of crystallization peak temperature, and its width at half height. In vitro studies of glasses and glass-ceramics in acelular SBF media showed bioactivity and the development of apatite layers The morphology, composition and adhesion of the apatite layer could be changed by substitution of Mg2+ by K+. Apatite layers were deposited on the surface of glass-ceramics of the nominal compositions with x=0 and 0.09, in contact with SBF at 37��C. The adhesion of the apatite layer was quantified by the scratch test technique, having been related with SBF?s immersion time, with composition and structure of the glass phase, and with the morphology of the crystalline phase of the glass-ceramics. The structure of three glasses (x=0, 0.045 and 0.090) were investigated by MAS-NMR ( 29Si and 31P), showing that the fraction of Q3 structural units increases with the contents of Mg, and that the structure of these glasses includes orthophosphate groups (PO43-) preferentially connected to Ca2+ ions. Mg2+ ions show preference towards the silicate network. Substitution of Mg2+ by K+ allowed one to change the bioactivity. FTIR data revealed octacalcium phosphate precipitation (Ca8H2(PO4)6.5H2O) in the glass without K, while the morphology of the layer acquires the shape of partially superimposed hemispheres, spread over the surface. The glasses with K present a layer of acicular hidroxyapatite, whose crystallinity and needles thickness tend to increase along with K content.

Automa����o e controlo de um sistema de armazenamento de bicicletas

A crescente procura da bicicleta como meio de transporte alternativo torna relevante a cria����o e desenvolvimento de infra-estruturas de apoio, tais como ciclovias e parques para bicicletas. Os sistemas tradicionais de parqueamento de bicicletas com recurso a correntes e cadeados n��o fornecem seguran��a nem comodidade. No entanto, come��am a surgir, em v��rias cidades do mundo, parque autom��ticos onde �� poss��vel guardar uma bicicleta em seguran��a, protegendo-a quer das intemp��ries quer de actos de vandalismo. Este trabalho apresenta uma proposta para um parque autom��tico de armazenamento de bicicletas, com recurso a caixas individualizadas que garantem a sua seguran��a, e tamb��m de outros bens que podem ser guardados junto da mesma, como por exemplo um capacete ou uma mochila. O sistema proposto no ��mbito deste trabalho �� um complemento ��s alternativas existentes. As vantagens apresentadas pelo sistema proposto s��o: a sua constru����o modular e personalizada; e a possibilidade de instala����o num terreno plano, sem recurso a obras de constru����o civil. O objectivo foi criar um projecto de automa����o e controlo de um prot��tipo, com base na proposta apresentada. O projecto de automa����o e controlo engloba a escolha dos sensores e dos actuadores. Para o dimensionamento dos motores foi necess��rio recorrer a um c��lculo simplificado da estrutura do rob�� manipulador. Foi feita a escolha dos sensores, actuadores e do controlador com base nos requisitos funcionais. A programa����o foi desenvolvida numa linguagem normalizada. O modelo desenvolvido poder�� servir de base para um projecto multidisciplinar entre v��rios departamentos do Instituto e dessa coopera����o poder�� surgir um novo projecto optimizado para produ����o e de menor custo.

Simulation of the Magnetic Induction Vector of a Magnetic Core to be Used in FFC NMR Relaxometry

This paper is a contribution for the assessment and comparison of magnet properties based on magnetic field characteristics particularly concerning the magnetic induction uniformity in the air gaps. For this aim, a solver was developed and implemented to determine the magnetic field of a magnetic core to be used in Fast Field Cycling (FFC) Nuclear Magnetic Resonance (NMR) relaxometry. The electromagnetic field computation is based on a 2D finite-element method (FEM) using both the scalar and the vector potential formulation. Results for the magnetic field lines and the magnetic induction vector in the air gap are presented. The target magnetic induction is 0.2 T, which is a typical requirement of the FFC NMR technique, which can be achieved with a magnetic core based on permanent magnets or coils. In addition, this application requires high magnetic induction uniformity. To achieve this goal, a solution including superconducting pieces is analyzed. Results are compared with a different FEM program.

O impacto do patroc��nio na inten����o de compra dos consumidores: estudo do caso do patroc��nio da volta a Portugal pela Liberty Seguros

O patroc��nio, enquanto meio de comunica����o, tem assumido uma import��ncia cada vez maior nas estrat��gias de marketing das organiza����es. O mercado empresarial atual obriga a que as marcas encontrem formas diferentes das convencionais de comunicar com os seus clientes e passar-lhes a sua mensagem. Assim, as empresas procuram, por via do patroc��nio, interagir com os consumidores e criar la��os afetivos que os liguem ��s marcas que representam. A presente investiga����o procura perceber de que forma uma a����o de patroc��nio pode ter impacto na inten����o de compra dos consumidores relativamente aos produtos/servi��os da marca patrocinadora. Pretende-se igualmente explorar os efeitos da congru��ncia entre o evento patrocinado e a marca patrocinadora, da atitude relativamente ao evento patrocinado e da atitude relativamente �� marca patrocinadora na inten����o de compra dos consumidores. Os resultados obtidos confirmam que o patroc��nio tem influ��ncia na inten����o de compra dos consumidores em rela����o aos produtos/servi��os da marca patrocinadora do evento. Confirmam tamb��m que a congru��ncia entre o evento e a marca, a atitude relativamente �� marca e a atitude relativamente ao evento s��o vari��veis que se encontram interligadas e que exercem um efeito de influ��ncia entre si, bem como em rela����o �� inten����o de compra dos consumidores.