Importance of the central nucleus of the amygdala on sodium intake caused by deactivation of lateral parabrachial nucleus

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Mirabegron relaxes urethral smooth muscle by a dual mechanism involving β3-adrenoceptor activation and α1-adrenoceptor blockade

Mirabegron is the first β3-adrenoceptor (AR) agonist approved for treatment of overactive bladder syndrome (OAB). This study aimed to investigate the effects of β3-adrenoceptor (AR) agonist mirabegron in mouse urethra. The possibility that mirabegron exerts α1-AR antagonism was also tested in rat smooth muscle preparations presenting α1A- (vas deferens and prostate), α1D- (aorta) and α1B-AR (spleen). Functional assays were carried out in mouse and rat isolated tissues. Competition assays for the specific binding of [(3) H]Prazosin to membrane preparations of HEK 293 cells expressing each of the human α1-ARs, as well as β-AR mRNA expression and cyclic AMP measurements in mouse urethra were performed. Mirabegron produced concentration-dependent urethral relaxations that were right shifted by the selective β3-AR antagonist L 748,337, but unaffected by β1- and β2-AR antagonists (atenolol and ICI 118,551, respectively). Mirabegron-induced relaxations were enhanced by the phosphodiesterase-4 inhibitor rolipram, and this agonist stimulated cAMP synthesis. Mirabegron also produced rightward shifts in urethral contractions induced by the α1-AR agonist phenylephrine. Schild regression analysis revealed that mirabegron behaves as a competitive antagonist of α1-AR in urethra, vas deferens and prostate (α1A-AR, pA2  ≅ 5.6) and aorta (α1D-AR, pA2  ≅ 5.4), but not in spleen (α1B-AR). The affinities estimated for mirabegron in functional assays were consistent with those estimated in radioligand binding with human recombinant α1A- and α1D-ARs (pKi ≅ 6.0). The effects of mirabegron in urethral smooth muscle are the result of β3-AR agonism together with α1A / α1D-AR antagonism.

Exenatide and sitagliptin decrease interleukin 1β, matrix metalloproteinase 9, and nitric oxide synthase 2 gene expression but does not reduce alveolar bone loss in rats with periodontitis

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Role of TRPV1 channels of the dorsal periaqueductal gray in the modulation of nociception and open elevated plus maze-induced antinociception in mice

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Role of the medial septal area on the cardiovascular, fluid and electrolytic responses to angiotensin II and cholinergic activation into the subfornical organ in rats

In the present study we investigated the effect of electrolytic lesion of the medial septal area (MSA) on the pressor and dipsogenic response to cholinergic activation and angiotensin II (ANGII) injection into the subfornical organ (SFO) in rats. In addition the effect of MSA lesion on the natriuresis, kaliuresis and diuresis after cholinergic activation of the SFO was also investigated. Sham- and MSA-lesioned rats with a stainless steel cannula implanted into the SFO was used. The injection of ANGII (12 ng) into the SFO in sham rats produced pressor (24 ± 2 mmHg) and dipsogenic (9.6 ± 1.1 ml/h) responses. MSA lesion, both acute (2-6 days) and chronic (15-19 days), reduced the pressor (14 ± 2 mmHg) and dipsogenic (2.7 ± 1 ml/h) responses to ANGII into SFO. The injection of the cholinergic agonist carbachol (2 nmol) into the SFO in sham rats produced pressor (48 ± 4 mmHg), dipsogenic (10 ± 1.2 ml/h), natriuretic (457 ± 58 μEq/2 h) and kaliuretic (249 ± 16 μEq/2 h) responses. Acute, but not chronic MSA lesion reduced the pressor (27 ± 3 mmHg), natriuretic (198 ± 55 μEq/2 h) and kaliuretic (128 ± 16 μEq/2 h) responses to carbachol into SFO. No change in the dipsogenic response to carbachol into the SFO was observed in MSA-lesioned rats. Antidiuresis after carbachol was observed only in MSA-lesioned rats. The present results show that the MSA plays a role on the pressor, natriuretic and kaliuretic responses to cholinergic activation of the SFO in rats and on the pressor and dipsogenic responses to ANGII into the same area. In addition, they provide circumstancial evidence for separate circuits subserving the dipsogenic response to central cholinergic and angiotensinergic activation. A facilited diuresis after MSA lesion is also suggested.

Role of alfa2-adrenoceptors in the lateral parabrachial nucleus in the control of body fluid homeostasis

Central α2-adrenoceptors and the pontine lateral parabrachial nucleus (LPBN) are involved in the control of sodium and water intake. Bilateral injections of moxonidine (α2-adrenergic/imidazoline receptor agonist) or noradrenaline into the LPBN strongly increases 0.3 M NaCl intake induced by a combined treatment of furosemide plus captopril. Injection of moxonidine into the LPBN also increases hypertonic NaCl and water intake and reduces oxytocin secretion, urinary sodium, and water excreted by cell-dehydrated rats, causing a positive sodium and water balance, which suggests that moxonidine injected into the LPBN deactivates mechanisms that restrain body fluid volume expansion. Pretreatment with specific α2-adrenoceptor antagonists injected into the LPBN abolishes the behavioral and renal effects of moxonidine or noradrenaline injected into the same area, suggesting that these effects depend on activation of LPBN α2-adrenoceptors. In fluid-depleted rats, the palatability of sodium is reduced by ingestion of hypertonic NaCl, limiting intake. However, in rats treated with moxonidine injected into the LPBN, the NaCl palatability remains high, even after ingestion of significant amounts of 0.3 M NaCl. The changes in behavioral and renal responses produced by activation of α2-adrenoceptors in the LPBN are probably a consequence of reduction of oxytocin secretion and blockade of inhibitory signals that affect sodium palatability. In this review, a model is proposed to show how activation of α2-adrenoceptors in the LPBN may affect palatability and, consequently, ingestion of sodium as well as renal sodium excretion.

Análise de parâmetros neuromusculares e cinemáticos dos chutes Bandal Chagui e Dolhô Chagui do Taekwondo

Pós-graduação em Desenvolvimento Humano e Tecnologias - IBRC

Avaliação bioquímica e imunohistoquímica dos efeitos subletais do tiametoxam sobre Apis mellifera (Hymenoptera, Apidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Current outlook and future perspectives of beef production in Brazil

Brazil is the world's largest beef exporter with the world's largest commercial cattle herd; however, the production cycle needs to be more efficient to supply internal and external demands in the future. Feedlot operations are currently a reality for the Brazilian beef cattle industry; nonetheless the beef cattle industry in Brazil is still based on grass-fed animals in which the Nellore breed predominates. At some point this constitutes an important advantage for Brazilian beef exportations because some countries look for “natural beef.” Brazilian packing plants regulate the use of antibiotics, especially ionophores used as growth promoters, on farms certified to export beef to European countries. In addition, the use of any implant or beta-agonist for cattle is forbidden in Brazil. From 1970 to 2006, the Brazilian bovine herd increased at 2.04%/year, total pasture at 0.07%/year, area with cultivated pasture at 3.5%/year, and ratio of animals/hectare of total pasture at 1.97%/year, whereas the area with natural pasture decreased at 2.26%/year. These trends alleviate some of the pressure on Brazilian authorities with respect to deforestation of the Amazon forest. Although Brazil had the greatest growth rate of enteric methane emissions, it also had the greatest growth rate of beef production, resulting in Brazil having a negative growth rate (–1.82%/year) of methane emissions per unit of product (kilogram of methane/kilogram of beef).

Envolvimento de receptores 5-HT1A no hipocampo ventral na regulação de comportamentos defensivos relacionados com a ansiedade generalizada e com o pânico

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Influência da Motilidade Gastrintestinal no processo de desintegração de comprimidos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)