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The synthesis of arborescent poly(gamma-benzyl L-glutamate) (PBG) molecules was achieved through successive grafting reactions of linear PBG chains. These linear PBG building blocks were obtained by the ring-opening polymerization of gamma-benzyl L-glutamic acid N-carboxyanhydride initiated with n-hexylamine. Cleavage of a fraction of the benzyl ester groups on a linear PBG substrate, followed by coupling with linear PBG side chains via standard peptide coupling techniques, yielded a comb-branched or generation zero (G0) arborescent PBG. Further cycles of partial deprotection and grafting reactions led to arborescent PBG molecules of the subsequent generations (G1-G3). Molecular weights reaching over 106 were obtained for G3 arborescent PBG, while maintaining narrow molecular weight distributions (Mw/Mn ≤ 1.06) for each generation. The arborescent PBG molecules displayed α-helix to randomly coiled chain conformation changes from N,N-dimethylformamide to dimethylsulfoxide. Amphiphilic copolymers were obtained by grafting the arborescent PBG substrates randomly with side chains of either poly(glycidol acetal), poly(ethylene oxide), or poly(γ-tert-butyl L-glutamate) via the same peptide coupling techniques used to generate arborescent PBG. Copolymers were also synthesized by a chain end grafting method, whereby the linear chain segments were coupled exclusively with the chain termini of the arborescent PBG substrates. Water-soluble species were obtained by removal of the acetal and tert-butyl protecting groups from the poly(glycidol acetal) and poly(γ-tert-butyl L-glutamate) side chains, respectively, while the copolymers with poly(ethylene oxide) side chains did not require further modifications. Dynamic light scattering (DLS) measurements on the arborescent copolymers in aqueous solutions revealed that unimolecular micelles were the dominant species for the chain end grafted arborescent copolymers, whereas the randomly grafted arborescent copolymers were either insoluble or displayed significant aggregation. The synthesis of arborescent copolymers with PBG cores was also achieved through “click” chemistry, using the copper-catalyzed azide-alkyne Huisgen cycloaddition (CuAAC) reaction. To that end, polyglycidol, poly(ethylene oxide), and poly(2-trimethylsilylethyl acrylate) chains terminally functionalized with azide groups were grafted onto either randomly or chain end alkyne-functionalized arborescent PBG substrates. DLS analysis revealed solubility trends similar to the arborescent copolymers obtained by the peptide coupling method. The CuAAC reaction enables the incorporation of a broader range of polymers into arborescent copolymer structures derived from PBG substrates.

L-glutamate (Glu) is the predominant excitatory neurotransmitter inthe mammalian central nervous system (CNS) and is associated with a widevariety of functions including motor behavior and sensory perception. Whilemicrodialysis methods have been used to record tonic levels of Glu, little isknown about the more rapid changes in Glu signals that may occur in awakeanimals. We have previously reported acute recording methods using anenzyme-based microelectrode array (MEA) with fast temporal resolution (800msec), that is minimally invasive and is capable of detecting low levels of Glu (andlt;0.2 ??M) in anesthetized animals with little interference from other analytes. Wehave made a series of modifications to the MEA design to allow for reliablemeasures in the brain of awake behaving rats. In these studies, wecharacterized the effects of chronic implantation of the MEA into the striatum andprefrontal cortex (PFC) of Fischer 344 and Long Evans rats. We measuredresting levels of Glu and local application of Glu for 7 days without a significantloss of sensitivity and determined that Glu measures due to exogenous Gluvaried between rat strain and brain region. In addition, we determined theviability of the recordings in the brains of awake animals. We performed studiesof tail-pinch induced stress which caused an increase in Glu in the striatum andPFC of Long Evans and Fischer 344 rats. Histological data show that chronicimplantation of our MEAs caused minimal injury to the CNS. Taken together, ourdata support that chronic recordings of tonic and phasic Glu can be carried out inawake rats reliably for 7 days in vivo allowing for longer term studies of Gluregulation in behaving rats.

The synthesis of arborescent poly(gamma-benzyl L-glutamate) (PBG) molecules was achieved through successive grafting reactions of linear PBG chains. These linear PBG building blocks were obtained by the ring-opening polymerization of gamma-benzyl L-glutamic acid N-carboxyanhydride initiated with n-hexylamine. Cleavage of a fraction of the benzyl ester groups on a linear PBG substrate, followed by coupling with linear PBG side chains via standard peptide coupling techniques, yielded a comb-branched or generation zero (G0) arborescent PBG. Further cycles of partial deprotection and grafting reactions led to arborescent PBG molecules of the subsequent generations (G1-G3). Molecular weights reaching over 106 were obtained for G3 arborescent PBG, while maintaining narrow molecular weight distributions (Mw/Mn ≤ 1.06) for each generation. The arborescent PBG molecules displayed α-helix to randomly coiled chain conformation changes from N,N-dimethylformamide to dimethylsulfoxide. Amphiphilic copolymers were obtained by grafting the arborescent PBG substrates randomly with side chains of either poly(glycidol acetal), poly(ethylene oxide), or poly(γ-tert-butyl L-glutamate) via the same peptide coupling techniques used to generate arborescent PBG. Copolymers were also synthesized by a chain end grafting method, whereby the linear chain segments were coupled exclusively with the chain termini of the arborescent PBG substrates. Water-soluble species were obtained by removal of the acetal and tert-butyl protecting groups from the poly(glycidol acetal) and poly(γ-tert-butyl L-glutamate) side chains, respectively, while the copolymers with poly(ethylene oxide) side chains did not require further modifications. Dynamic light scattering (DLS) measurements on the arborescent copolymers in aqueous solutions revealed that unimolecular micelles were the dominant species for the chain end grafted arborescent copolymers, whereas the randomly grafted arborescent copolymers were either insoluble or displayed significant aggregation. The synthesis of arborescent copolymers with PBG cores was also achieved through “click” chemistry, using the copper-catalyzed azide-alkyne Huisgen cycloaddition (CuAAC) reaction. To that end, polyglycidol, poly(ethylene oxide), and poly(2-trimethylsilylethyl acrylate) chains terminally functionalized with azide groups were grafted onto either randomly or chain end alkyne-functionalized arborescent PBG substrates. DLS analysis revealed solubility trends similar to the arborescent copolymers obtained by the peptide coupling method. The CuAAC reaction enables the incorporation of a broader range of polymers into arborescent copolymer structures derived from PBG substrates.

This work reports a novel biocompatible and biodegradable arborescent amphiphilic polypept(o)ides-based polymer poly(γ-benzyl L-glutamate)-co-poly(γ-tert-butyl L-glutamate)-g-polysarcosine (P(BG-co-Glu(OtBu))-g-PSar) as a smart dual-responsive targeting drug vehicle. The synthesis pathway in this work highlighted the grafting reaction improvement of the polypeptides core and using polysarcosine (PSar) corona as a coating agent. The responsiveness of the polymer is caused by the pH sensitivity of the polypeptides and the reducible linker introduced between the core and corona. While adding the tripeptides arginine, glycine, and aspartate (RGD) as a ligand on the unimolecular micelles’ surface increases the targeting ability of the polymer. During the building of the arborescent, the coupling sites were controlled by using γ-tert-butyl L-glutamate (Glu(OtBu)-NCA) as a second monomer besides γ-benzyl L-glutamate (BG-NCA) since the deprotection conditions are different for Bz and tBu groups. Knowing the coupling sites provides accuracy in calculating the molecular weight (MW) of graft polymers since it facilitates the determination of the grafting yield (Gy). The arborescent unimolecular micelles were formulated by coating the hydrophobic core with PSar hydrophilic corona. The distribution of the coupling sites on the substrates in the last generation yielded end-grafted and randomly-grafted unimolecular micelles. A comparison between those micelles by DLS, TEM, and AFM revealed that the end-grafted micelles showed more uniformity in terms of morphology and size distribution. Also, the surface modification achieved via RGD addition increased the shape uniformity and contributed to avoiding the particles’ aggregation. The sizes and shapes of end-grafted unimolecular micelles match the drug delivery systems (DDSs) requirements. Doxorubicin (DOX) was encapsulated physically into the unimolecular micelles to study the drug loading capacity (DLC) and drug loading efficiency (DLE). The maximum DLC and DLE were 14% and 28% w/w, respectively. The drug release profiles were investigated in healthy- and cancer-mimicking media. The results showed that in cancer-mimicking microenvironment (low pH and high glutathione (GSH) content), the drug diffused out the micelles faster. In addition, a slower drug release was noticed for RGD decorated unimolecular micelles. Finally, the biocompatibility, cytotoxicity, and cellular uptake of the unimolecular micelles were studied. The obtained results were promising as the arborescent unimolecular micelles showed excellent biocompatibility; meanwhile, the DOX-loaded unimolecular micelles have good cytotoxicity compared to free DOX. RGD targeting ligand contributes to increasing the cellular uptake and supports the sustained release.

L-glutamate plays a vital role in central nervous system. It is a neurotransmitterassociated with several neurological disorders like Parkinson's disease, epilepsyand stroke. Continuous and fast monitoring of this neurotransmitter has become amajor concern for neuroscientists throughout the world. A simple, sensitive, and reliable L-glutamate microsensor with short responsetime has been developed using ceramic-based microelectrode arrays with platinum recording sites. The electrodes were modified by electrodeposition of Platinum black (Pt-black) to detect hydrogen peroxide (H2O2) which was produced by enzymatic reactions of glutamate oxidase immobilized on the electrode surface. Modification of Pt electrodes with Pt-black has been adoptedbecause the microscale roughness of Pt-black increases the effective surface area of the electrode and promotes efficiency of H2O2 electro-oxidation. The modified Pt recording sites were coated with m-phenylenediamine (mPD) and L-glutamate oxidase (L-GluOx). mPD acts as an barrier for extracellular interferents such as ascorbic acid and dopamine, thus increasing the selectivity of electrode for Glutamate (Glu). This modified microsensor was highly sensitive to H2O2(686.3??156.48 ??AmM-1cm-2), and Glutamate (492.2??112.67 ??AmM-1cm-2) at 700mV versus Ag/AgCl reference. Deposition of Pt nano-particles on recording sites enhanced the sensitivity to H2O2 by 2 times and the sensitivity to glutamate by 1.5 times.

The effects of stimulation of the A5 cell group of the caudal ventrolateral pons electrically or with L-glutamate on heart rate and blood pressure were determined in rabbits. Electrical stimulation caused blood pressure increases and reflex bradycardia. L-glutamate caused decreases in blood pressure and heart rate which were blocked by the L-glutamate antagonist aminophosphoheptanoic acid. Transection of the brainstem at the level of the midbrain did not alter the effects of either electrical or chemical stimulation. Lesions of the nucleus and tractus solitarius (NTS) attenuated the effects of L-glutamate, but did not change the effectiveness electrical stimulation. Injections of 6-hydroxydopamine three to four weeks before the experiments blocked the effects of electrical stimulation but only reduced the effects of L-glutamate injection. The A5 group may have two functional subdivisions. Some A5 cells may produce blood pressure depressor and bradycardiac effects by means of projections to the NTS and the spinal cord. Other A5 cells may produce blood pressure presser effects by means of projections to the spinal cord.

Submitted by Rosivalda Pereira (mrs.pereira@ufma.br) on 2017-06-14T17:28:23Z No. of bitstreams: 1 CarolineVale.pdf: 4135607 bytes, checksum: d26bf0afb2078fe97033389d010e9282 (MD5) / Made available in DSpace on 2017-06-14T17:28:23Z (GMT). No. of bitstreams: 1 CarolineVale.pdf: 4135607 bytes, checksum: d26bf0afb2078fe97033389d010e9282 (MD5) Previous issue date: 2016-12-13 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPQ) / Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (FAPEMA) / Metabolic syndrome (MS) is defined as a set of interrelated risk factors that contribute to type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). SM also causes harmful effects on the reproductive system, especially for women, as it reducies ovulatory rates, increasies the number of abortions and late pregnancy complications, which increase the risk of infertility. As a form of treatment approaches are adopted both non-pharmacologic and pharmacologic. In this context, the use of alternative therapies with natural products has emerged as a safer and less associated with worsening of MS risk factors. Syzygium cumini (jambolan) is a species of Asian origin, but cultivated and used throughout the world for its anti-hyperglycemic, anti-hiperlipemiantes and antioxidants. Through these actions, we sought to investigate whether the hydroalcoholic extract of the leaves of S. cumini (EHSyz) improves the metabolic changes and consequently, changes in reproductive function in rats with induced obesity L-monosodium glutamate (MSG) a dose 4g/Kg/day. Wistar female rats were divided into the following groups: CTRL group (treated with NaCl 0.9% 0.1 ml / 100g / day v.o,); MSG group (treated with NaCl 0.9% 0.1 ml / 100g / day V.O.); EHSyz obese group (treated with EHSyz at a dose of 500mg / kg / day, V.O.), each for 60 days. The administration EHSyz promoted with retention of weight gain, reduction Lee index and improved glycolipid profile, with reduced serum triglyceride levels by 60.7% and 29.7% compared to cholesterol total.O EHSyz even avoided introduction resistance table in the treated rats. However, despite the improvement in oligociclicidade, the extract was not able to improve reproductive impairment of the treated rats. Thus, we conclude that treatment with EHSyz produced marked effects on metabolic parameters in obese rats without interfering with the reproductive capacity of the same. / A síndrome metabólica (SM) é definida como um conjunto de fatores de risco interrelacionados que contribuem para o diabetes mellitus tipo 2 (DM2) e doenças cardiovasculares (DCV). A SM também provoca efeitos deletérios sobre o sistema reprodutor, especialmente feminino, com redução de taxas ovulatórias, aumento do número de abortos, complicações tardias da gravidez, que elevam o risco de infertilidade. Como forma de tratamento, são adotadas abordagens tanto não farmacológicos quanto farmacológicas. Nesse contexto, o uso de terapias alternativas com produtos naturais tem se destacado como uma forma menos associada ao agravamento dos fatores de risco da SM. Syzygium cumini (jambolão) é uma espécie vegetal de origem asiática, porém cultivada e utilizada em todo o mundo por suas propriedades anti-hiperglicemiantes, anti-hiperlipemiantes e antioxidantes. Mediante tais ações, buscamos investigar se o extrato hidroalcoólico das folhas de S. cumini (EHSyz) melhora as alterações metabólicas e, consequentemente, as alterações da função reprodutiva de ratas com obesidade induzida por L-glutamato monossódico (MSG) na dose 4g/Kg/dia. Fêmeas Wistar foram divididas nos seguintes grupos: grupo CTRL (tratado com NaCl 0,9% 0,1mL/100g/dia v.o,); grupo MSG (tratado com NaCl 0,9% 0,1mL/100g/dia v.o.); grupo obeso EHSyz (tratado com EHSyz na dose de 500mg/kg/dia, v.o.), todos durante 60 dias. A administração com EHSyz promoveu manutenção do ganho de peso, redução do índice de Lee e melhora do perfil glicolipídico, com redução dos níveis séricos de triglicérides em 60,7 % e 29,7 % em relação ao colesterol total. O EHSyz evitou ainda a instauração do quadro de resistência nas ratas tratadas. Entretanto apesar da melhora na oligociclicidade, o extrato não foi capaz de melhorar o comprometimento reprodutivo das ratas tratadas. Desta forma, concluímos que o tratamento com EHSyz produziu efeitos acentuados sobre parâmetros metabólicos de ratas obesas sem interferir na capacidade reprodutiva das mesmas.

In this study, tetraphenylthiophenen (TP) with aggregation-induced emission enhancement (AIEE) property is served as terminal and central fluorophores of poly(£^-benzyl-L-glutamate) (PBLG)-based polymers of TP1PBLG and TP2PBLG, respectively, to probe for the relationship between the secondary structure (£\-helix) of polypeptides and the ALEE-operative fluorescence (FL). Intermolecular aggregation of the central TP unit in the di-substituted TP2PBLG is sterically blocked by the large £\-helical PBLG chains, which lead to the reduced AIEE-oriented FL. On the contrast, the terminal TP units in TP1PBLG can easily approach each other to form aggregates with strong FL. Factor (e.g. solvent annealing) controlling the fraction of £\-helix chain also varies the corresponding emission intensity. Conformational difference between TP1PBLG and TP2PBLG evaluated from the infrared and the X-ray (wide- and small-angle) diffraction spectra is also used to verify its influence on the AIEE-operative FL behavior.

Made available in DSpace on 2016-06-02T19:22:56Z (GMT). No. of bitstreams: 1 4404.pdf: 1810111 bytes, checksum: 6d3d450fd7a8a81c835b1a82a6176dba (MD5) Previous issue date: 2012-03-02 / Financiadora de Estudos e Projetos / The central nervous system (CNS) has an important role in maintaining the composition and volume of body fluids for the appropriate tissue perfusion. An important area of the CNS that receives cardiorespiratory afferents is the nucleus of the solitary tract (NTS) that has several types of neurotransmitters, includingL-glutamate and adenosine 5'-triphosphate (ATP). Neuroendocrine changes that occur during sodium depletion could change glutamatergi c and purinergic neurotransmissions into the NTS. Thus, in this study, we investigated : 1) the effects of sodium depletion on cardiorespiratory responses before and after injections of L -glutamate and α,β-methyleneadenosine 5′-triphosphate (α,β-methyl ATP, a selective P2X purinergic receptor agonist) into the NTS of unanesthetized and sodium depleted rats; 2) the cardiorespiratory responses of the injection of α,β-methyl ATP before and after the blockade of P2 receptor purinergic antagonist with suramin (non-selective P2 purinergic receptor antagonist) into NTS of unanesthetized and normovolemic rats and 3) to describe the autonomic components involved with the cardiovascular responses after injection of α,β-methyl ATP into the NTS. Male Holtzman rats with a cannula implanted into the NTS and catheters inserted into the femoral artery and vein were used. Ventilation (VE) was measured by whole body plethysmograph method. In relation to objective 1, the cardiorespiratory parameters were measured in normovolemic (before sodium depletion), depleted (24 h after sodium depletion) and repleted rats (two hours after free access to 0.3 M NaCl and water). Sodium depletion was induced by the treatment with the diuretic furosemide (20 mg/kg of body weight) injected subcut aneously (s.c.) followed by 24 h of sodium -deficient diet. Sodium depletion did not modify baseline MAP (104 ± 4 mmHg, vs. normovolemic: 105 ± 4 mmHg) or HR (334 ± 20 bpm, vs. normovolemic: 379 ± 13 bpm) but increased the VE (708 ± 107 ml/min/kg, vs. normovolemic: 478 ± 60 ml/min/kg). This effect was due to increase on tidal volume (VT, 7 ± 0.6 ml/kg, vs. normovolemic: 5 ± 0.4 ml/kg) without effect on the respiratory frequency (fR, 99 ± 8 cpm, vs. normovolemic: 85 ± 6 cpm). In repleted rats, VE did not return to normal level (640 ± 33 ml/min/kg, vs. normovolemic: 478 ± 60 ml/min/kg). Unilateral injections of L-glutamate (1 and 5 nmol/100 nl) into the NTS produced pressor response (17 ± 3 and 36 ± 3 mmHg, respectively, vs. saline: 3 ± 1 mmHg), bradycardia (-130 ± 15 and -169 ± 10 bpm, respectively, vs. saline: -13 ± 6 bpm) and the hyperventilation (233 ± 44 and 495 ± 114 ml/min/kg, respectively, vs. saline: 32 ± 26 ml/min/kg). Sodium depletion reduced pressor responses (4 ± 3 mmHg and 13 ± 4 mmHg, respectively) and hyperventilation (-112 ± 112 and 7 ± 115 ml/min/kg, respectively) and did not change bradycardia (-116 ± 30 and -156 ± 18 bpm, respectively). Unilateral injections of α,β-methyl ATP (2 nmol/100 nl) into the NTS also produced pressor response (36 ± 5 mmHg, vs. saline: 3 ± 1 mmHg), bradycardia (-194 ± 18 bpm, vs. saline: -13 ± 6 bpm) and did not change VE (54 ± 96 ml/min/kg, vs. saline: 32 ± 26 ml/min/kg). Sodium depletion reduced pressor response (24 ± 5 mmHg), VE ( -147 ± 184 ml/min/kg) and did not change bradycardia (-168 ± 22 bpm). In relation to objective 2, the results showed that injection of α,β-methyl ATP (2 nmol/100 nl) into NTS produced pressor response (24 ± 4 mmHg e -187 ± 39 bpm, respectively) and these responses were reduced 15 min after injection of suramin into NTS ipsilateral (13 ± 2 mmHg e -80 ± 18 bpm). Injection of α,β-methyl ATP into NTS produced no significantly change in VE. In relation to objective 3, the results showed that injection of α,β-methyl ATP (2 nmol/100 nl) into NTS promote pressor and bradycardic response (32 ± 5 mmHg and -183 ± 21 bpm). The pre-treatment with the alpha1 -adrenoceptor antagonist prazosin (1 mg/kg bw, i.v.) attenuated the increase in MAP (+10 ± 3 mmHg) without changing the bradycardic response (-192 ± 21 bpm) evoked by injection of α,β-methyl ATP into NTS. The pre-treatment with the cholinergic muscarinic antagonist, methyl-atropine (1 mg/kg bw, i.v.) did not changed the pressor response (+31 ± 6 mmHg) and abolished the bradycardic response (+21 ± 6 bpm) induced by injection of α,β-methyl ATP into the NTS. The results suggest that neuroendocrine changes produced by sodium depletion (increased level of circulating ANG II, aldosterone and the desactivation of the volume receptors and baroreceptors) may change the glutamatergic and purinergic neurotransmissions into the NTS. Furthermore, activation of P2X receptors in the NTS activates both the sympathetic and parasympathetic nervous system to produce pressor and bradycardic responses, respectively, without changing ventilation / O sistema nervoso central (SNC) possui um papel fundamental na manutenção da composição e do volume dos líquidos corporais, para a adequada perfusão tecidual. Uma importante área do SNC que recebe aferências cardiorrespiratórias é o núcleo do trato solitário (NTS) que possui vários tipos de neurotransmissores, dentre eles o L-glutamato e adenosina-5´-trifosfato (ATP). Mudanças neuroendócrinas que ocorrem durante a depleção de sódio poderiam alterar as neurotransmissões glutamatérgica e purinérgica no NTS. Assim, neste estudo, tivemos 3 objetivos: 1) investigar os efeitos da depleção de sódio nas respostas cardiorrespiratórias antes e após a injeção de L-glutamato e α,β-metileno adenosina 5’ trifosfato (α,β-metil ATP, agonista seletivo de receptor purinérgico P2X) no NTS de ratos não anestesiados; 2) investigar as respostas cardiorrespiratórias à injeção de α,β-metil ATP no NTS antes e após o bloqueio dos receptores purinérgicos P2 com o suramin (antagonista não-seletivo de receptores P2) no NTS de ratos não anestesiados e normovolêmicos e 3) caracterizar os componentes autonômicos envolvidos nas respostas cardiovasculares após a injeção de α,β-metil ATP no NTS. Foram utilizados ratos Holtzman com cânulas implantadas no NTS e com cateter inserido na artéria e veia femoral. As medidas de ventilação (VE) foram obtidas pelo método de pletismografia de corpo inteiro. Com relação ao objetivo 1, os parâmetros cardiorrespiratórios foram medidos em ratos normovolêmicos (antes da depleção de sódio), depletados (24 h após a depleção de sódio) e ratos repletos (2 h após o livre acesso a NaCl 0,3 M e água). A depleção de sódio foi induzida pelo tratamento com o diurético furosemida (20 mg/Kg do peso corporal) injetado subcutaneamente (s.c.) acompanhado de uma dieta deficiente em sódio por 24 h. A depleção de sódio não modificou a PAM basal (104 ± 4 mmHg, vs. normovolêmicos: 105 ± 4 mmHg) nem a FC (334 ± 20 bpm, vs. normovolêmico: 379 ± 13 bpm) mas aumentou a VE (708 ± 107 ml/min/kg, vs. normovolêmico: 478 ± 60 ml/min/kg). Este efeito ocorreu devido a um aumento do volume corrente (VC, 7 ± 0,6 ml/kg, vs. normovolêmico: 5 ± 0,4 ml/kg) sem alterar a frequência respiratória (fR, 99 ± 8 cpm, vs. normovolêmicos: 85 ± 6 cpm). Em ratos repletos, a VE não retornou ao nível normal (640 ± 33 ml/min/kg vs. normovolêmico: 478 ± 60 ml/min/kg). Injeções unilaterais de Lglutamato (1 e 5 nmol/100 nl) no NTS produziu resposta pressora (17 ± 3 e 36 ± 3 mmHg, respectivamente, vs. salina: 3 ± 1 mmHg), bradicardia (-130 ± 15 e -169 ± 10 bpm, respectivamente, vs. salina: -13 ± 6 bpm) e hiperventilação (233 ± 44 e 495 ± 114 ml/min/kg, respectivamente, vs. salina: 32 ± 26 ml/min/kg). A depleção de sódio reduziu a resposta pressora (4 ± 3 mmHg e 13 ± 4 mmHg, respectivamente) e hiperventilação (-112 ± 112 e 7 ± 115 ml/min/kg, respectivamente) e não alterou a bradicardia (-116 ± 30 e -156 ± 18 bpm, respectivamente). Injeção unilateral de α,β-metil ATP (2 nmol/100 nl) no NTS também produziu resposta pressora (36 ± 5 mmHg, vs. salina: 3 ± 1 mmHg), bradicardia (- 194 ± 18 bpm, vs. salina: -13 ± 6 bpm) e não modificou a VE (54 ± 96 ml/min/kg, vs. salina: 32 ± 26 ml/min/kg). A depleção de sódio reduziu a resposta pressora (24 ± 5 mmHg), a VE (-147 ± 184 ml/min/kg) e não alterou a bradicardia (-168 ± 22 bpm). Com relação ao objetivo 2, os resultados mostraram que a injeção de α,β-metil ATP (2 nmol/100 nl) no NTS promoveu resposta pressora e bradicárdica (24 ± 4 mmHg e -187 ± 39 bpm, respectivamente) e estas respostas foram reduzidas aos 15 minutos após a injeção de suramin no NTS ipsilateral (13 ± 2 mmHg e -80 ± 18 bpm). A injeção de α,β-metil ATP no NTS não promoveu alterações significativas na VE. Com relação ao objetivo 3, os resultados mostraram que as injeções de α,β-metil ATP (2 nmol/100 nl) no NTS promoveu resposta pressora e bradicardia (+32 ± 5 mmHg e -183 ± 21 bpm). O pré-tratamento com o antagonista de receptor alfa-1 adrenérgico, prazosin (1 mg/kg de peso corporal, i.v.), atenuou o aumento da PAM (+10 ± 3 mmHg) sem alterar a bradicardia (-192 ± 21 bpm) provocada pela injeção de α,β-metil-ATP no NTS e o pré-tratamento com o antagonista colinérgico muscarínico, metil-atropina (1 mg/kg de peso corporal, i.v.) não alterou a resposta pressora (+31 ± 6 mmHg) e aboliu a bradicardia (+21 ± 6 bpm) induzida pela injeção de α,β-metil ATP no NTS. Os resultados sugerem que alterações neuroendócrinas produzidas pela depleção de sódio (aumento dos níveis de ANG II e aldosterona circulantes e a desativação de receptores de volume e dos barorreceptores) podem alterar as neurotransmissões glutamatérgica e purinérgica no NTS. Além disso, a ativação dos receptores purinérgicos P2X no NTS ativa simultaneamente o sistema nervoso simpático e parassimpático para produzir respostas pressora e bradicárdica, respectivamente, sem alterar a ventilação pulmonar.