Maria Andréia Delbin

Interaction between Advanced Glycation End Products Formation and Vascular Responses in Femoral and Coronary Arteries from Exercised Diabetic Rats

Background The majority of studies have investigated the effect of exercise training (TR) on vascular responses in diabetic animals (DB), but none evaluated nitric oxide (NO) and advanced glycation end products (AGEs) formation associated with oxidant and antioxidant activities in femoral and coronary arteries from trained diabetic rats. Our hypothesis was that 8-week TR would alter AGEs levels in type 1 diabetic rats ameliorating vascular responsiveness. Methodology/Principal Findings Male Wistar rats were divided into control sedentary (C/SD), sedentary diabetic (SD/DB), and trained diabetic (TR/DB). DB was induced by streptozotocin (i.p.: 60 mg/kg). TR was performed for 60 min per day, 5 days/week, during 8 weeks. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP), phenylephrine (PHE) and tromboxane analog (U46619) were obtained. The protein expressions of eNOS, receptor for AGEs (RAGE), Cu/Zn-SOD and Mn-SOD were analyzed. Tissues NO production and reactive oxygen species (ROS) generation were evaluated. Plasma nitrate/nitrite (NOx −), superoxide dismutase (SOD), catalase (CAT), thiobarbituric acid reactive substances (TBARS) and Nε-(carboxymethyl) lysine (CML, AGE biomarker). A rightward shift in the concentration-response curves to ACh was observed in femoral and coronary arteries from SD/DB that was accompanied by an increase in TBARS and CML levels. Decreased in the eNOS expression, tissues NO production and NOx − levels were associated with increased ROS generation. A positive interaction between the beneficial effect of TR on the relaxing responses to ACh and the reduction in TBARS and CML levels were observed without changing in antioxidant activities. The eNOS protein expression, tissues NO production and ROS generation were fully re-established in TR/DB, but plasma NOx − levels were partially restored. Conclusion Shear stress induced by TR fully restores the eNOS/NO pathway in both preparations from non-treated diabetic rats, however, a massive production of AGEs still affecting relaxing responses possibly involving other endothelium-dependent vasodilator agents, mainly in coronary artery.

Exercise training ameliorates the impairment of endothelial and nitrergic corpus cavernosum responses in diabetic rats

AIMS The effect of exercise training (ET) on vascular responsiveness in diabetes mellitus has been largely well studied. However, limited studies have investigated the effects of ET on functional responses of the corpus cavernosum (CC) in diabetic animals. Therefore, the aim of this study was to investigate whether prior ET prevents the impairment of erectile function in streptozotocin-induced diabetic rats. MAIN METHODS Rats were exercised for four weeks prior to the induction of diabetes, and then again for another 4 weeks thereafter. Concentration-response curves to acetylcholine, sodium nitroprusside, Y-27632, BAY 412272 and phenylephrine (PE) were obtained in CC. The excitatory and inhibitory effects of electrical-field stimulation were also evaluated. KEY FINDINGS Plasma SOD levels were markedly decreased in the sedentary diabetic group (D-SD) as compared to control sedentary animals (C-SD), approximately 53% (P<0.05) and this reduction was restored in trained diabetic animals. Physical training restored the impairment of endothelium-dependent and -independent relaxation responses seen in the D-SD group. The potency values for Y-27632 in the CC were significantly reduced in the D-SD group, which was reversed by physical training. The impairment of electrical-field stimulation (EFS)-induced relaxation seen in the D-SD group was restored by physical training. On the other hand, both EFS-induced contractions and concentration-response curves to PE in cavernosal strips were not modified by either diabetes or physical training. SIGNIFICANCE Practice of regular physical exercise may be an important approach in preventing erectile dysfunction associated with diabetes mellitus by re-establishment of the balance between NO production and its inactivation.

Platelet hyperaggregability in high-fat fed rats: A role for intraplatelet reactive-oxygen species production

BackgroundAdiposity greatly increases the risk of atherothrombotic events, a pathological condition where a chronic state of oxidative stress is reported to play a major role. This study aimed to investigate the involvement of (NO)-soluble guanylyl cyclase (sGC) signaling pathway in the platelet dysfunction from high fat-fed (HFF) rats.MethodsMale Wistar rats were fed for 10 weeks with standard chow (SCD) or high-fat diet (HFD). ADP (10 μM)- and thrombin (100 mU/ml)-induced washed platelet aggregation were evaluated. Measurement of intracellular levels of ROS levels was carried out using flow cytometry. Cyclic GMP levels were evaluated using ELISA kits.ResultsHigh-fat fed rats exhibited significant increases in body weight, epididymal fat, fasting glucose levels and glucose intolerance compared with SCD group. Platelet aggregation induced by ADP (n = 8) and thrombin from HFD rats (n = 8) were significantly greater (P < 0.05) compared with SCD group. Platelet activation with ADP increased by 54% the intraplatelet ROS production in HFD group, as measured by flow cytometry (n = 6). N-acetylcysteine (NAC; 1 mM) and PEG-catalase (1000 U/ml) fully prevented the increased ROS production and platelet hyperaggregability in HFD group. The NO donors sodium nitroprusside (SNP; 10 μM) and SNAP (10 μM), as well as the NO-independent soluble guanylyl cyclase stimulator BAY 41-2272 (10 μM) inhibited the platelet aggregation in HFD group with lower efficacy (P < 0.05) compared with SCD group. The cGMP levels in response to these agents were also markedly lower in HFD group (P < 0.05). The prostacyclin analogue iloprost (1 μM) reduced platelet aggregation in HFD and SCD rats in a similar fashion (n = 4).ConclusionsMetabolic abnormalities as consequence of HFD cause platelet hyperaggregability involving enhanced intraplatelet ROS production and decreased NO bioavailability that appear to be accompanied by potential defects in the prosthetic haem group of soluble guanylyl cyclase.

Influence of acute pancreatitis on the in vitro responsiveness of rat mesenteric and pulmonary arteries

BackgroundAcute pancreatitis is an inflammatory disease characterized by local tissue injury and systemic inflammatory response leading to massive nitric oxide (NO) production and haemodynamic disturbances. Therefore, the aim of this work was to evaluate the vascular reactivity of pulmonary and mesenteric artery rings from rats submitted to experimental pancreatitis.Male Wistar rats were divided into three groups: saline (SAL); tauracholate (TAU) and phospholipase A2 (PLA2). Pancreatitis was induced by administration of TAU or PLA2 from Naja mocambique mocambique into the common bile duct of rats, and after 4 h of duct injection the animals were sacrificed. Concentration-response curves to acetylcholine (ACh), sodium nitroprusside (SNP) and phenylephrine (PHE) in isolated mesenteric and pulmonary arteries were obtained. Potency (pEC50) and maximal responses (EMAX) were determined. Blood samples were collected for biochemical analysis.ResultsIn mesenteric rings, the potency for ACh was significantly decreased from animals treated with TAU (about 4.2-fold) or PLA2 (about 6.9-fold) compared to saline group without changes in the maximal responses. Neither pEC50 nor EMAX values for Ach were altered in pulmonary rings in any group. Similarly, the pEC50 and the EMAX values for SNP were not changed in both preparations in any group. The potency for PHE was significantly decreased in rat mesenteric and pulmonary rings from TAU group compared to SAL group (about 2.2- and 2.69-fold, for mesenteric and pulmonary rings, respectively). No changes were seen in the EMAX for PHE. The nitrite/nitrate (NOx-) levels were markedly increased in animals submitted to acute pancreatitis as compared to SAL group, approximately 76 and 68% in TAU and PLA2 protocol, respectively.ConclusionAcute pancreatitis provoked deleterious effects in endothelium-dependent relaxing response for ACh in mesenteric rings that were strongly associated with high plasma NOx- levels as consequence of intense inflammatory responses. Furthermore, the subsensitivity of contractile response to PHE in both mesenteric and pulmonary rings might be due to the complications of this pathological condition in the early stage of pancreatitis.

Papel do exercício físico na isquemia/reperfusão pulmonar e resposta inflamatória

Advances in new technologies associated with improvement of knowledge in medicine have promoted important development in therapeutic and preventive approaches in an attempt to diminish complications following cardiothoracic process involving ischemia/ reperfusion (IR). Nevertheless, postoperative pulmonary injuries remain high and are considered one of the most frequent complications after cardiothoracic surgery. Thus, new strategies with prophylactic actions are crucial in cardiovascular area in an attempt to reduce complications and to improve patient life. It is well documented that exercise training is a non-pharmacological tool to prevent and/or treat cardiovascular and endocrine-metabolic diseases. The aim of this review was to provide an update of several studies pulmonary IR process and its local and systemic complications and the role of inflammatory response. Furthermore, this review focused on the effects of exercise training on the pulmonary IR as an important strategy to diminish its complications. This review shows that few studies exist regarding the health-promoting physical exercise in cardiothoracic surgery and how important is necessary to increase studies in this area. Recently, studies from our laboratory showed beneficial effects of exercise training in experimental model of pulmonary IR. Collectively, data show that physical preconditioning for patients is very important approach to reduce postsurgical complications as well as diminish the time of hospitalization which includes a specialized personal trainer in the health team. Moreover, this preventive strategy might improve patient recovery and would lead to consuming less resources of the health care system. This review included experimental studies in English and Portuguese found in SciELO and MEDLINE (from 1987 to 2008) and also classics texts related to the title.

Beneficial Effects of Physical Training on the Cardio-Inflammatory Disorder Induced by Lung Ischemia/Reperfusion in Rats

Our laboratory demonstrated that training program attenuated the inflammatory responses in lung ischemia/reperfusion (IR). Considering the importance of the inflammatory responses on the cardiovascular system, we evaluate the effect of physical training on the vascular responsiveness and its underlying mechanism after lung IR. Male Wistar rats were submitted to run training and lung IR. Concentration–response curves for relaxing and contracting agents were obtained. Protein expressions of SOD-1 and p47phox, plasma nitritre/nitrate (NOx−) and interleukin 6 (IL-6) were evaluated. A decreased in the potency for acetylcholine and phenylephrine associated with an upregulation of the p47phox expression were found after Lung IR as well as an increase in IL-6 and NOx− levels. Run training attenuated the vascular dysfunction that was accompanied by reduction of the p47phox protein expression and IL-6 levels. Our findings show the beneficial effect of training on the vascular function that was associated with reduction in inflammatory response in lung IR.

Interaction between serotoninergic-and β-adrenergic receptors signaling pathways in rat femoral artery.

BACKGROUND Coronary heart disease has been widely studied in cardiovascular research. However, patients with peripheral artery disease (PAD) have worst outcomes compared to those with coronary artery disease. Therefore, pharmacological studies using femoral artery are highly relevant for a better understanding of the pathophysiologic responses of the PAD. OBJECTIVE The aim of this study was to evaluate the pharmacologic properties of the contractile and relaxing agents in rat femoral artery. METHODS Concentration response curves to the contractile phenylephrine (PE) and serotonin (5-HT) and the relaxing agents isoproterenol (ISO) and forskolin were obtained in isolated rat femoral artery. For relaxing responses, tissues were precontracted with PE or 5-HT. RESULTS The order rank potency in femoral artery was 5-HT > PE for contractile responses. In tissues precontracted with 5-HT, relaxing responses to isoproterenol was virtually abolished as compared to PE-contracted tissues. Forskolin, a stimulant of adenylyl cyclase, partially restored the relaxing response to ISO in 5-HT-precontracted tissues. CONCLUSION An interaction between β-adrenergic- and serotoninergic- receptors signaling pathway occurs in femoral artery. Moreover, this study provides a new model to study serotoninergic signaling pathway under normal and pathological conditions which can help understanding clinical outcomes in the PAD.FUNDAMENTO: A doenca coronaria tem sido amplamente estudada em pesquisas cardiovasculares. No entanto, pacientes com doenca arterial periferica (DAP) tem piores resultados em comparacao aqueles com doenca arterial coronariana. Portanto, os estudos farmacologicos com arteria femoral sao altamente relevantes para a melhor compreensao das respostas clinicas e fisiopatologicas da DAP. OBJETIVO: Avaliar as propriedades farmacologicas dos agentes contrateis e relaxantes na arteria femoral de ratos. METODOS: As curvas de resposta de concentracao a fenilefrina contratil (FC) e a serotonina (5-HT) e os agentes relaxantes isoproterenol (ISO) e forskolina foram obtidos na arteria femoral de ratos isolada. Para as respostas ao relaxamento, os tecidos foram contraidos com FC ou 5-HT. RESULTADOS: A potencia de classificacao na arteria femoral foi de 5-HT > FC para as respostas contrateis. Em tecidos contraidos com 5-HT, as respostas de relaxamento ao isoproterenol foram praticamente abolidas em comparacao aos tecidos contraidos com FC. A forskolina, um estimulante da adenilil ciclase, restaurou parcialmente a resposta de relaxamento ao ISO em tecidos contraidos com 5-HT. CONCLUSAO: Ocorre uma interacao entre as vias de sinalizacao dos receptores β-adrenergicos e serotoninergicos na arteria femoral. Alem disso, esta pesquisa fornece um novo modelo para estudar as vias de sinalizacao serotoninergicas em condicoes normais e patologicas que podem ajudar a compreender os resultados clinicos na DAP.

Interação entre as vias de sinalização de receptores serotoninérgicos e Β-adrenérgicos em artéria femoral de ratos

BACKGROUND Coronary heart disease has been widely studied in cardiovascular research. However, patients with peripheral artery disease (PAD) have worst outcomes compared to those with coronary artery disease. Therefore, pharmacological studies using femoral artery are highly relevant for a better understanding of the pathophysiologic responses of the PAD. OBJECTIVE The aim of this study was to evaluate the pharmacologic properties of the contractile and relaxing agents in rat femoral artery. METHODS Concentration response curves to the contractile phenylephrine (PE) and serotonin (5-HT) and the relaxing agents isoproterenol (ISO) and forskolin were obtained in isolated rat femoral artery. For relaxing responses, tissues were precontracted with PE or 5-HT. RESULTS The order rank potency in femoral artery was 5-HT > PE for contractile responses. In tissues precontracted with 5-HT, relaxing responses to isoproterenol was virtually abolished as compared to PE-contracted tissues. Forskolin, a stimulant of adenylyl cyclase, partially restored the relaxing response to ISO in 5-HT-precontracted tissues. CONCLUSION An interaction between β-adrenergic- and serotoninergic- receptors signaling pathway occurs in femoral artery. Moreover, this study provides a new model to study serotoninergic signaling pathway under normal and pathological conditions which can help understanding clinical outcomes in the PAD.FUNDAMENTO: A doenca coronaria tem sido amplamente estudada em pesquisas cardiovasculares. No entanto, pacientes com doenca arterial periferica (DAP) tem piores resultados em comparacao aqueles com doenca arterial coronariana. Portanto, os estudos farmacologicos com arteria femoral sao altamente relevantes para a melhor compreensao das respostas clinicas e fisiopatologicas da DAP. OBJETIVO: Avaliar as propriedades farmacologicas dos agentes contrateis e relaxantes na arteria femoral de ratos. METODOS: As curvas de resposta de concentracao a fenilefrina contratil (FC) e a serotonina (5-HT) e os agentes relaxantes isoproterenol (ISO) e forskolina foram obtidos na arteria femoral de ratos isolada. Para as respostas ao relaxamento, os tecidos foram contraidos com FC ou 5-HT. RESULTADOS: A potencia de classificacao na arteria femoral foi de 5-HT > FC para as respostas contrateis. Em tecidos contraidos com 5-HT, as respostas de relaxamento ao isoproterenol foram praticamente abolidas em comparacao aos tecidos contraidos com FC. A forskolina, um estimulante da adenilil ciclase, restaurou parcialmente a resposta de relaxamento ao ISO em tecidos contraidos com 5-HT. CONCLUSAO: Ocorre uma interacao entre as vias de sinalizacao dos receptores β-adrenergicos e serotoninergicos na arteria femoral. Alem disso, esta pesquisa fornece um novo modelo para estudar as vias de sinalizacao serotoninergicas em condicoes normais e patologicas que podem ajudar a compreender os resultados clinicos na DAP.

Circulating Concentrations of Adipocytokines and Their Receptors in the Isolated Corpus Cavernosum and Femoral Artery from Trained Rats on a High-Fat Diet

Background: The aim of the present study was to evaluate different signaling pathways by which exercise training would interfere in endothelial function in obesity. Therefore, we examined adipocytokine levels and their receptors in the corpus cavernosum and femoral artery from trained rats on a high-fat diet. Methods: Functional experiments were performed in control sedentary and trained rats, and sedentary (h-SD) and trained male Wistar rats on a high-fat diet (h-TR). Nitric oxide (NO) and reactive oxygen species (ROS) were evaluated in vascular tissue. Circulating adipocytokines and their receptors were analyzed. Results: In the h-SD group, the maximal responses to acetylcholine (ACh) were reduced in the femoral artery and corpus cavernosum as well as the electrical field stimulation, accompanied by an increase in circulating insulin, leptin, TNF-α, MCP-1, and PAI-1. Downregulation of ObR protein expression in the femoral artery was observed without alterations in AdipoR1 and TNFR1 in both preparations. A positive effect was observed in the h-TR group regarding the relaxation response to ACh and circulating adipocytokines, resulting in increased NO production and reduced ROS generation. Exercise restored the ObR protein expression only in the femoral artery. Conclusion: Aerobic exercise training ameliorated the inflammatory adipocytokines and restored the relaxation responses in the corpus cavernosum and femoral artery in rats on a high-fat diet.

Interacción entre las vías de señalización de receptores serotoninérgicos y β-adrenégicos en la arteria femoral de ratones

BACKGROUND Coronary heart disease has been widely studied in cardiovascular research. However, patients with peripheral artery disease (PAD) have worst outcomes compared to those with coronary artery disease. Therefore, pharmacological studies using femoral artery are highly relevant for a better understanding of the pathophysiologic responses of the PAD. OBJECTIVE The aim of this study was to evaluate the pharmacologic properties of the contractile and relaxing agents in rat femoral artery. METHODS Concentration response curves to the contractile phenylephrine (PE) and serotonin (5-HT) and the relaxing agents isoproterenol (ISO) and forskolin were obtained in isolated rat femoral artery. For relaxing responses, tissues were precontracted with PE or 5-HT. RESULTS The order rank potency in femoral artery was 5-HT > PE for contractile responses. In tissues precontracted with 5-HT, relaxing responses to isoproterenol was virtually abolished as compared to PE-contracted tissues. Forskolin, a stimulant of adenylyl cyclase, partially restored the relaxing response to ISO in 5-HT-precontracted tissues. CONCLUSION An interaction between β-adrenergic- and serotoninergic- receptors signaling pathway occurs in femoral artery. Moreover, this study provides a new model to study serotoninergic signaling pathway under normal and pathological conditions which can help understanding clinical outcomes in the PAD.FUNDAMENTO: A doenca coronaria tem sido amplamente estudada em pesquisas cardiovasculares. No entanto, pacientes com doenca arterial periferica (DAP) tem piores resultados em comparacao aqueles com doenca arterial coronariana. Portanto, os estudos farmacologicos com arteria femoral sao altamente relevantes para a melhor compreensao das respostas clinicas e fisiopatologicas da DAP. OBJETIVO: Avaliar as propriedades farmacologicas dos agentes contrateis e relaxantes na arteria femoral de ratos. METODOS: As curvas de resposta de concentracao a fenilefrina contratil (FC) e a serotonina (5-HT) e os agentes relaxantes isoproterenol (ISO) e forskolina foram obtidos na arteria femoral de ratos isolada. Para as respostas ao relaxamento, os tecidos foram contraidos com FC ou 5-HT. RESULTADOS: A potencia de classificacao na arteria femoral foi de 5-HT > FC para as respostas contrateis. Em tecidos contraidos com 5-HT, as respostas de relaxamento ao isoproterenol foram praticamente abolidas em comparacao aos tecidos contraidos com FC. A forskolina, um estimulante da adenilil ciclase, restaurou parcialmente a resposta de relaxamento ao ISO em tecidos contraidos com 5-HT. CONCLUSAO: Ocorre uma interacao entre as vias de sinalizacao dos receptores β-adrenergicos e serotoninergicos na arteria femoral. Alem disso, esta pesquisa fornece um novo modelo para estudar as vias de sinalizacao serotoninergicas em condicoes normais e patologicas que podem ajudar a compreender os resultados clinicos na DAP.