A new mixed model of periodontitis-induced preeclampsia: A pilot study.

OBJECTIVES/BACKGROUND: Recent studies have shown that periodontal disease is strongly related to gestational complications such as preeclampsia (PE). PE is responsible for 42% of maternal deaths worldwide and kills approximately 76 000 women a year. In addition, children born under PE conditions are at increased risk of hospitalization due to metabolic disorders, epilepsy, and other complications. Numerous reviews and clinical studies on PE have been published, but the mechanisms underlying the relationship between periodontal disease and PE and the way periodontopathogens alter vascular response in pregnant women remain unclear. METHODS: This study aims to verify whether periodontal disease induces PE by using the association of two periodontitis (PD) models: ligature and oral Porphyromonas gingivalis (P. gingivalis) W83 inoculation in Wistar rats. At gestational day 5, the ligature was placed on each mandibular first molar, which was followed by daily oral P. gingivalis inoculation for 15 days. At gestational day 19, urine was collected, and invasive arterial pressure was measured. The animals were euthanized, and plasma and tissues were collected. RESULTS: After 15 days of the association of ligature and P. gingivalis inoculation, the animals presented the characteristic symptoms of PE: altered blood pressure, proteinuria, and change in litter size (number of pups) and pup weight when compared to the control group (p < .005). The PE animals also presented greater bone porosity, trabecular separation, and reduced bone volume in the hemimandibles, as well as altered inflammatory response. The level of cytokine IL-6 was higher in the PE group than in the control group (p < .005). CONCLUSION: The association of two PD models effectively induced PE. To our knowledge, this is the first study on the oral use of P. gingivalis for PE induction. Our results support the importance of PD as a possible cause for PE development, opening an important new avenue to study cause and consequence relationships in inflammation and PE due to exposure to periodontal infection.

Reconstrução de defeito de parede abdominal e vulva após ressecção de endometriomas extracavitários / Reconstruction of abdominal wall and vulvar defects after endometriosis resection

Introdução: Endometriose é a presença de tecido endometrial funcionante (glândulas endometriais e estroma) em localização fora da cavidade endometrial. Implantes endometrióticos extrapélvicos têm sido ocasionalmente descritos na literatura. Métodos: Este é um relato de caso de uma paciente do serviço de cirurgia plástica do autor, operada em setembro de 2013 em um hospital de Brasília-DF. O trabalho seguiu os princípios de Helsinque e o termo de consentimento livre e esclarecido foi realizado. Resultados: O trabalho se trata de uma paciente de 30 anos que apresentava dismenorreia, dor e parestesia em região inguinal direita, nódulo endurecido em grande lábio direito com cicatrizes de duas ressecções de focos de endometriose. A equipe de ginecologia realizou ressecção endoscópica das lesões cavitárias, do conteúdo do canal inguinal, do nódulo no grande lábio direito, da cicatriz umbilical e parte da aponeurose. Após se instalarem os defeitos de parede abdominal e vulva, a cirurgia plástica realizou a reconstrução com retalho de abdome inferior randômico, baseado lateralmente, como um dos vértices de uma zetaplastia. Conclusão: O retalho descrito no trabalho é uma alternativa na reconstrução da região inguinal e vulva, em casos de grandes defeitos, obtendo um resultado satisfatório.

Introduction: Endometriosis is characterized by the presence of functional endometrial tissue (endometrial glands and stroma) outside the uterine cavity. However, only a few cases of extrapelvic endometriosis have been described in the literature. Methods: This study reports the case of a patient from the author's plastic surgery service who underwent surgery in September 2013 at a hospital in Brasília, Federal District, Brazil. The study was conducted according to the principles of the Declaration of Helsinki, and the patient signed an informed consent form. Results: A 30-year-old female patient presented with dysmenorrhea, pain, and paresthesia in the right inguinal region as well as a firm nodule in the labia majora with scars from two surgical resections of endometriosis. The gynecology team performed endoscopic resection of the uterine cavity lesions, inguinal canal content, nodules in the right labia majora, umbilical scar, and part of the aponeurosis. The abdominal wall and vulvar defects caused by the resection were repaired using a laterally based random lower abdominal flap as one of the vertices of a Z-plasty. Conclusion: The flap described in this study is an alternative and satisfactory method for repairing large defects in the inguinal and vulvar regions.

Retalho interpolado de sulco nasogeniano em único estágio para reconstrução de defeitos nasais e de canto interno da órbita / Single-stage nasolabial interpolation flap for reconstructing defects of the nose and inner corner of the eye

Introdução: Os retalhos interpolados são opções cirúrgicas eficazes para reconstruções de defeitos cutâneos em várias áreas do corpo, inclusive na face. O retalho proposto dispensa cuidados pós-operatórios com o pedículo exposto e pode ser realizado em tempo único. O objetivo é avaliar a utilidade do retalho interpolado de sulco nasogeniano (RISN) em ilha, na reconstrução de segmentos nasais e do canto interno da órbita, bem como discutir refinamentos em seu design e execução. Métodos: Estudo retrospectivo de prontuários de pacientes com defeitos nasais ou de canto interno da órbita, e que foram reparados com retalho interpolado do sulco nasogeniano. Todos os retalhos foram confeccionados de maneira randômica, realizando-se túnel subcutâneo para evitar pedículo exposto e cicatriz que comunicasse a área doadora e o defeito. Resultados: cinco pacientes foram incluídos no estudo, com idade entre 30 e 92 anos. Em todos os casos foi realizada biópsia de congelação intraoperatória que revelou margens livres de doença, orientando a extensão da ressecção. O CBC foi encontrado em 4 pacientes e o CEC em um paciente. Não houve complicações como sangramento pós-operatório ou necrose. Bons resultados funcionais e estéticos foram alcançados em todos os pacientes. Discussão: Vale ressaltar a versatilidade do retalho nasogeniano interpolado, sendo capaz de auxiliar na reconstrução de defeitos extensos não apenas de asa, ponta e columela nasais, mas também de dorso e canto medial do olho. Destaca-se também o aspecto estético mais favorável do pedículo do retalho interpolado em ilha comparado ao de transposição. Conclusão: O RISN interpolado em único estágio é uma opção confiável na reconstrução de segmentos faciais. Apresenta boa vascularização, possibilidade se ser realizado em único tempo e pode ser utilizado para cobertura nos locais onde há poucas opções reconstrutivas disponíveis.

Introduction: Interpolation flaps are effective surgical options for reconstructing skin defects in various areas of the body, including the face. The proposed flap does not require postoperative care with the pedicle exposed and can be performed in a single surgery. The objective is to evaluate the usefulness of the nasolabial interpolation island flap (NIF) for reconstructing nasal segments and the inner corner of the eye, as well as discuss improvements in its design and performance. Methods: In this retrospective study, medical records of patients with nasal defects that were repaired with a nasolabial interpolation flap were reviewed. All flaps were created with a subcutaneous tunnel to avoid pedicle exposure and prevent scar connection with the donor area and the defect. Results: Five patients aged 30­92 years were included. In all cases, intraoperative frozen biopsy revealed disease-free margins, indicating the extent of the resection. Basal cell carcinoma was found in four patients and squamous cell carcinoma in one. There were no complications such as postoperative bleeding or necrosis. Good functional and aesthetic results were achieved. Discussion: The NIF can help in the reconstruction of extensive defects of the nasal ala, tip, columella, and medial dorsum as well as the corner of the eye. We also highlight the more favorable aesthetic aspect of the pedicle in the interpolation island versus transposition flap. Conclusion: The single-stage NIF flap is a reliable option for reconstructing facial segments as it has good vascularization, can be performed in a single surgery, and can be used to cover places where few other reconstructive options are available.

Antioxidant and antihypertensive responses to oral nitrite involves activation of the Nrf2 pathway.

Impaired redox balance contributes to the cardiovascular alterations of hypertension and activation of nuclear factor erythroid 2-related factor 2 (Nrf2) pathway may counteract these alterations. While nitrite recycles back to NO and exerts antioxidant and antihypertensive effects, the mechanisms involved in these responses are not fully understood. We hypothesized that nitrite treatment of two-kidney, one-clip (2K1C) hypertensive rats activates the Nrf2 pathway, promotes the transcription of antioxidant genes, and improves the vascular redox imbalance and dysfunction in this model. Two doses of oral nitrite were studied: 15 mg/kg and the sub-antihypertensive dose of 1 mg/kg. Nitrite 15 mg/kg (but not 1 mg/kg) decreased blood pressure and increased circulating plasma nitrite and nitrate. Both doses blunted hypertension-induced increases in mesenteric artery reactive oxygen species concentrations assessed by DHE technique and restored the impaired mesenteric artery responses to acetylcholine. While 2K1C hypertension decreased nuclear Nrf2 accumulation, both doses of nitrite increased nuclear Nrf2 accumulation and mRNA expression of Nrf2-regulated genes including superoxide dismutase-1 (SOD1), catalase (CAT), glutathione peroxidase (GPX), thioredoxin-1(TRDX-1) and -2 (TRDX-2). To further confirm nitrite-mediated antioxidant effects, we measured vascular SOD and GPX activity and we found that nitrite at 1 or 15 mg/kg increased the activity of both enzymes (P < 0.05). These results suggest that activation of the Nrf2 pathway promotes antioxidant effects of nitrite, which may improve the vascular dysfunction in hypertension, even when nitrite is given at a sub-antihypertensive dose. These findings may have many clinical implications, particularly in the therapy of hypertension and other cardiovascular diseases.

Avaliação prospectiva das repercussões no perfil lipídico das cirurgias que envolvem lipoaspiração e dermolipectomias / Prospective assessment of the repercussions on the lipid profile of surgeries involving liposuction and dermolipectomies

Introdução: Lipoaspiração associada a dermolipectomias é o procedimento cirúrgico mais comumente realizado em cirurgia plástica. Apesar de ser considerada uma cirurgia extremamente segura, algumas considerações devem ser levantadas a respeito dos possíveis efeitos metabólicos que essas cirurgias possam causar. O desenvolvimento da técnica tumescente de lipoaspiração permitiu a remoção de grande quantidade de gordura de modo mais seguro. O objetivo é comparar as variações do perfil lipídico em pós-operatório precoce e tardio de pacientes submetidos à lipoaspiração e dermolipectomias. Métodos: Entre outubro de 2006 e junho de 2012, 40 pacientes do sexo feminino candidatas a cirurgias que envolviam lipoaspiração e dermolipectomias foram acompanhadas prospectivamente e o perfil lipídico foi analisado por meio de exames no pré-operatório e no pós-operatório. As cirurgias realizadas foram: mamoplastia + lipoaspiração, abdominoplastia + lipoaspiração e lipoabdominoplastia + mamoplastia. Resultados: Das 40 pacientes que foram acompanhadas no estudo, 20 pacientes do sexo feminino foram selecionadas (após a aplicação dos critérios de exclusão). Em consonância com nosso estudo, Cazes, em 1996, demonstrou que após 12 meses de pós-operatório de lipoabdominoplastia não houve alteração do perfil lipídico das pacientes. Conclusão: Após análise pré- e pós-operatória de 20 pacientes, observamos que não há alterações estatísticas significantes em relação ao perfil lipídico com tendência de equilíbrio das aferições em um ano em patamares próximos aos observados no pré-operatório.

Introduction: Liposuction associated with dermolipectomies is the most commonly performed surgical procedure in plastic surgery. Although regarded as an extremely safe surgery, some considerations must be taken on the possible metabolic effects of these surgeries. The development of the tumescent technique in liposuction allowed the safer removal of large amounts of fat. The objective is to compare lipid profile variations in the early and late postoperative period in patients undergoing liposuction and dermolipectomies. Methods: Between October 2006 and June 2012, 40 female patients who were candidates for surgeries involving liposuction and dermolipectomies were prospectively followed, and the lipid profile was analyzed through preoperative and postoperative examinations. The surgeries performed were mammoplasty + liposuction, abdominoplasty + liposuction, and lipoabdominoplasty + mammoplasty. Results: Of the 40 female patients who were followed, 20 were selected (after applying the exclusion criteria). In agreement with our study, in 1996, Cazes showed that there were no changes in the lipid profile of patients 12 months after lipoabdominoplasty. Conclusion: After a preoperative and postoperative analysis of 20 patients, it was observed that there were no statistically significant changes in the lipid profile and that the measurements after 1 year were close to those obtained in the preoperative period.

Nitrite treatment downregulates vascular MMP-2 activity and inhibits vascular remodeling in hypertension independently of its antihypertensive effects.

Hypertension is associated with cardiovascular remodeling. Given that impaired redox state activates matrix metalloproteinase (MMP)- 2 and promotes vascular remodeling, we hypothesized that nitrite treatment at a non-antihypertensive dose exerts antioxidant effects and attenuates both MMP-2 activation and vascular remodeling of hypertension. We examined the effects of oral sodium nitrite at antihypertensive (15 mg/kg) or non-antihypertensive (1 mg/kg) daily dose in hypertensive rats (two kidney, one clip; 2K1C model). Sham-operated and 2K1C hypertensive rats received vehicle or nitrite by gavage for four weeks. Systolic blood pressure decreased only in hypertensive rats treated with nitrite 15 mg/Kg/day. Both low and high nitrite doses decreased 2K1C-induced vascular remodeling assessed by measuring aortic cross-sectional area, media/lumen ratio, and number of vascular smooth muscle cells/aortic length. Both low and high nitrite doses decreased 2K1C-induced vascular oxidative stress assessed in situ with the fluorescent dye DHE and with the lucigenin chemiluminescence assay. Vascular MMP-2 expression and activity were assessed by gel zymography, Western blot, and in situ zymography increased with hypertension. While MMP-2 levels did not change in response to both doses of nitrite, both doses completely prevented hypertension-induced increases in vascular MMP activity. Moreover, incubation of aortas from hypertensive rats with nitrite at 1-20 µmol/L reduced gelatinolytic activity by 20-30%. This effect was fully inhibited by the xanthine oxidase (XOR) inhibitor febuxostat, suggesting XOR-mediated generation of nitric oxide (NO) from nitrite as a mechanism explaining the responses to nitrite. In vitro incubation of aortic extracts with nitrite 20 µmol/L did not affect MMP-2 activity. These results show that nitrite reverses the vascular structural alterations of hypertension, independently of anti-hypertensive effects. This response is mediated, at least in part, by XOR and is attributable to antioxidant effects of nitrite blunting vascular MMP-2 activation. Our findings suggest nitrite therapy to reverse structural alterations of hypertension.

Reconstrução mamária com o retalho miocutâneo do grande dorsal e implantes: avaliação de estratégias adotadas para melhoria dos resultados e avaliação de satisfação pelo Breast-Q / Breast reconstruction with a latissimus dorsi myocutaneous flap and implants: evaluation of strategies adopted to improve the results and evaluation of satisfaction by Breast-Q

Introdução: O trabalho descreve 14 anos em reconstrução mamária com o retalho miocutâneo do grande dorsal (RGD) e implantes mamários. O objetivo é delinear experiência com o RGD e implantes mamários, programações das ilhas de pele e detalhes da dissecção, transposição de retalho e colocação do implante sob dupla camada muscular, estratégias para minimizar os danos na área doadora, estratégias de simetrização mamária e reconstrução do complexo areolopapilar, associado a avaliação do questionário Breast-Q. Métodos: Foi realizada revisão de prontuários entre abril de 2003 a junho de 2017. Resultados: No período 76 pacientes foram reconstruídas com o RGD, com idade média de 50,09 anos, sendo 11 bilaterais, 34 mama direita e 31 mama esquerda. 41 imediatas, 22 tardias e 13 de resgate. A média de satisfação foi 72,36% por meio do Breast-Q. Conclusão: Concluímos e comprovamos com o questionário do Breast-Q que a indicação precisa aliada a técnica de reconstrução proposta com plano duplo subpeitoral associada a cobertura do RDG, propicia uma loja mais segura, diminuído o índice de rippling.

Introduction: The paper describes a 14-year experience with breast reconstruction using a latissimus dorsi myocutaneous flap (LDMF) and breast implants. The objective was to delineate the experience with LDMF and breast implants, skin island schedules and dissection details, flap transposition and placement of the implant under a double layer, strategies to minimize damage in the donor area, and strategies of breast symmetry and reconstruction of the nipple-areola complex, in association with evaluation using the Breast-Q questionnaire. Methods: A review of medical records was performed between April 2003 and June 2017. Results: In the period, 76 patients with a mean age of 50.09 years underwent reconstruction with a LDMF, which was bilateral in 11, for the right breast in 34, for the left breast in 31, immediate in 41, late in 22, and for rescue in 13. Conclusion: We conclude and verified with the Breast-Q questionnaire that with a precise indication, the proposed reconstruction technique with a double subpectoral plane and coverage with a LDMF is safer with a lower complication rate.

Nitrite exerts antioxidant effects, inhibits the mTOR pathway and reverses hypertension-induced cardiac hypertrophy.

Cardiac hypertrophy is a common consequence of chronic hypertension and leads to heart failure and premature death. The anion nitrite is now considered as a bioactive molecule able to exert beneficial cardiovascular effects. Previous results showed that nitrite attenuates hypertension-induced increases in reactive oxygen species (ROS) production in the vasculature. Whether antioxidant effects induced by nitrite block critical signaling pathways involved in cardiac hypertrophy induced by hypertension has not been determined yet. The Akt/mTOR signaling pathway is responsible to activate protein synthesis during cardiac remodeling and is activated by increased ROS production, which is commonly found in hypertension. Here, we investigated the effects of nitrite treatment on cardiac remodeling and activation of this hypertrophic signaling pathway in 2 kidney-1 clip (2K1C) hypertension. Sham and 2K1C rats were treated with oral nitrite at 1 or 15 mg/kg for four weeks. Nitrite treatment (15 mg/kg) reduced systolic blood pressure and decreased ROS production in the heart tissue from hypertensive rats. This nitrite dose also blunted hypertension-induced activation of mTOR pathway and cardiac hypertrophy. While the lower nitrite dose (1 mg/kg) did not affect blood pressure, it exerted antioxidant effects and tended to attenuate mTOR pathway activation and cardiac hypertrophy induced by hypertension. Our findings provide strong evidence that nitrite treatment decreases cardiac remodeling induced by hypertension as a result of its antioxidant effects and downregulation of mTOR signaling pathway. This study may help to establish nitrite as an effective therapy in hypertension-induced cardiac hypertrophic remodeling.

The matricellular protein TSP1 promotes human and mouse endothelial cell senescence through CD47 and Nox1.

Senescent cells withdraw from the cell cycle and do not proliferate. The prevalence of senescent compared to normally functioning parenchymal cells increases with age, impairing tissue and organ homeostasis. A contentious principle governing this process has been the redox theory of aging. We linked matricellular protein thrombospondin 1 (TSP1) and its receptor CD47 to the activation of NADPH oxidase 1 (Nox1), but not of the other closely related Nox isoforms, and associated oxidative stress, and to senescence in human cells and aged tissue. In human endothelial cells, TSP1 promoted senescence and attenuated cell cycle progression and proliferation. At the molecular level, TSP1 increased Nox1-dependent generation of reactive oxygen species (ROS), leading to the increased abundance of the transcription factor p53. p53 mediated a DNA damage response that led to senescence through Rb and p21cip, both of which inhibit cell cycle progression. Nox1 inhibition blocked the ability of TSP1 to increase p53 nuclear localization and p21cip abundance and its ability to promote senescence. Mice lacking TSP1 showed decreases in ROS production, p21cip expression, p53 activity, and aging-induced senescence. Conversely, lung tissue from aging humans displayed increases in the abundance of vascular TSP1, Nox1, p53, and p21cip Finally, genetic ablation or pharmacological blockade of Nox1 in human endothelial cells attenuated TSP1-mediated ROS generation, restored cell cycle progression, and protected against senescence. Together, our results provide insights into the functional interplay between TSP1 and Nox1 in the regulation of endothelial senescence and suggest potential targets for controlling the aging process at the molecular level.

Endothelial Nox1 oxidase assembly in human pulmonary arterial hypertension; driver of Gremlin1-mediated proliferation.

Pulmonary arterial hypertension (PAH) is a rapidly degenerating and devastating disease of increased pulmonary vessel resistance leading to right heart failure. Palliative modalities remain limited despite recent endeavors to investigate the mechanisms underlying increased pulmonary vascular resistance (PVR), i.e. aberrant vascular remodeling and occlusion. However, little is known of the molecular mechanisms responsible for endothelial proliferation, a root cause of PAH-associated vascular remodeling. Lung tissue specimens from PAH and non-PAH patients and hypoxia-exposed human pulmonary artery endothelial cells (ECs) (HPAEC) were assessed for mRNA and protein expression. Reactive oxygen species (ROS) were measured using cytochrome c and Amplex Red assays. Findings demonstrate for the first time an up-regulation of NADPH oxidase 1 (Nox1) at the transcript and protein level in resistance vessels from PAH compared with non-PAH patients. This coincided with an increase in ROS production and expression of bone morphogenetic protein (BMP) antagonist Gremlin1 (Grem1). In HPAEC, hypoxia induced Nox1 subunit expression, assembly, and oxidase activity leading to elevation in sonic hedgehog (SHH) and Grem1 expression. Nox1 gene silencing abrogated this cascade. Moreover, loss of either Nox1, SHH or Grem1 attenuated hypoxia-induced EC proliferation. Together, these data support a Nox1-SHH-Grem1 signaling axis in pulmonary vascular endothelium that is likely to contribute to pathophysiological endothelial proliferation and the progression of PAH. These findings also support targeting of Nox1 as a viable therapeutic option to combat PAH.

Avaliação dos parâmetros pressóricos intra-abdominal e pulmonar em pacientes submetidos à abdominoplastia / Evaluation of pressure parameters intra-abdominal and thoracic in patients submitted to abdominoplasty

Introdução: O abdome é um segmento estético-funcional importante na caracterização do contorno corporal. A confecção da plicatura do reto abdominal pode ocasionar diversos transtornos como o aumento da pressão intra-abdominal e torácica. Assim, este estudo tem como objetivo avaliar os parâmetros de pressão abdominal e pulmonar em pacientes submetidos à abdominoplastia com lipoaspiração. Métodos: Estudo longitudinal prospectivo descritivo. As pacientes foram submetidas à lipoabdominoplastia com lipoaspiração de flancos pelo mesmo cirurgião plástico sênior. A mensuração da pressão intra-abdominal foi feita por meio do uso de um dispositivo acoplado à sonda vesical de demora do paciente e a pressão intratorácica foi aferida por meio do monitor do aparelho de ventilação. As medições foram feitas antes e após a plicatura e durante a posição de Fowler. Resultados: O tempo médio do ato operatório foi de 4 horas e 8 minutos. A pressão intra-abdominal antes e após a plicatura do músculo reto abdominal variou de 2 a 11 cm H2O e 5 a 16 cm H2O, respectivamente. A pressão intratorácica antes e após a plicatura do músculo reto abdominal variou de 13 a 17 cm H2O e 14 a 18 cm H2O, respectivamente. A pressão intra-abdominal em posição de Fowler variou de 6 a 23 cm H2O. A pressão intratorácica em posição de Fowler variou de 15 a 19 cm H2O. Foi observado um caso de deiscência, um caso de seroma e um caso de desconforto respiratório. Conclusão: Os resultados elucidam que a plicatura do reto abdominal ocasiona o aumento da pressão intra-abdominal e pulmonar sem gerar alterações sistêmicas significativas.

Introduction: The abdomen is an important aesthetic and functional segment in the characterization of body contouring. The plication of the rectus abdominis may cause various problems to the patient such as increased intra-abdominal and thoracic pressure. Thus, this study aims to evaluate abdominal pressure and pulmonary parameters in patients undergoing abdominoplasty with liposuction. Methods: This is a descriptive longitudinal prospective study. All patients underwent the lipoabdominoplasty with liposuction of flanks by the same senior plastic surgeon. The intra-abdominal pressure was measured by a device attached to indwelling urinary catheter of the patient and intra-thoracic pressure was measured by the ventilation device monitor. Measurements were made before and after plication and in Fowler's position. Results: Mean surgery time was 4 hours and 08 minutes. Intra-abdominal pressure before and after plication of the rectus abdominis ranged from 2 to 11 cm H2O and 5-16 cm H2O, respectively. Intra-thoracic pressure before and after plication of the rectus abdominis ranged from 13 to 17 cm H2O and 14-18 cm H2O respectively. The intra-abdominal pressure in Fowler's position ranged from 6 to 23 cm H2O. The intra-thoracic pressure in Fowler's position ranged from 15 to 19 cm H2O. One case of small dehiscence, one case of seroma and one case of respiratory distress were observed. Conclusion: The results demonstrate that plication of the rectus abdominis increases intra-abdominal and pulmonary pressure without generating significant systemic changes.

Oral nitrite circumvents antiseptic mouthwash-induced disruption of enterosalivary circuit of nitrate and promotes nitrosation and blood pressure lowering effect.

The nitric oxide (NO•) metabolites nitrite and nitrate exert antihypertensive effects by mechanisms that involve gastric formation of S-nitrosothiols. However, while the use of antiseptic mouthwash (AM) is known to attenuate the responses to nitrate by disrupting its enterosalivary cycle, there is little information about whether AM attenuates the effects of orally administered nitrite. We hypothesized that the antihypertensive effects of orally administered nitrite would not be prevented by AM because, in contrast to oral nitrate, oral nitrite could promote S-nitrosothiols formation in the stomach without intereference by AM. Chronic effects of oral nitrite or nitrate were studied in two-kidney, one-clip (2K1C) hypertensive rats (and normotensive controls) treated with AM (or vehicle) once/day. We found that orally administered nitrite exerts antihypertensive effects that were not affected by AM. This finding contrasts with lack of antihypertensive responses to oral nitrate in 2K1C hypertensive rats treated with AM. Nitrite and nitrate treatments increased plasma nitrites, nitrates, and S-nitrosothiols concentrations. However, while treatment with AM attenuated the increases in plasma nitrite concentrations after both nitrite and nitrate treatments, AM attenuated the increases in S-nitrosothiols in nitrate-treated rats, but not in nitrite-treated rats. Moreover, AM attenuated vascular S-nitrosylation (detected by the SNO-RAC method) after nitrate, but not after nitrite treatment. Significant correlations were found between the hypotensive responses and S-nitrosothiols, and vascular S-nitrosylation levels. These results show for the first time that oral nitrite exerts antihypertensive effects notwithstanding the fact that antiseptic mouthwash disrupts the enterosalivary circulation of nitrate. Our results support a major role for S-nitrosothiols formation resulting in vascular S-nitrosylation as a key mechanism for the antihypertensive effects of both oral nitrite and nitrate.

Binding of EBP50 to Nox organizing subunit p47phox is pivotal to cellular reactive species generation and altered vascular phenotype.

Despite numerous reports implicating NADPH oxidases (Nox) in the pathogenesis of many diseases, precise regulation of this family of professional reactive oxygen species (ROS) producers remains unclear. A unique member of this family, Nox1 oxidase, functions as either a canonical or hybrid system using Nox organizing subunit 1 (NoxO1) or p47(phox), respectively, the latter of which is functional in vascular smooth muscle cells (VSMC). In this manuscript, we identify critical requirement of ezrin-radixin-moesin-binding phosphoprotein 50 (EBP50; aka NHERF1) for Nox1 activation and downstream responses. Superoxide (O2 (•-)) production induced by angiotensin II (AngII) was absent in mouse EBP50 KO VSMC vs. WT. Moreover, ex vivo incubation of aortas with AngII showed a significant increase in O2 (•-) in WT but not EBP50 or Nox1 nulls. Similarly, lipopolysaccharide (LPS)-induced oxidative stress was attenuated in femoral arteries from EBP50 KO vs. WT. In silico analyses confirmed by confocal microscopy, immunoprecipitation, proximity ligation assay, FRET, and gain-/loss-of-function mutagenesis revealed binding of EBP50, via its PDZ domains, to a specific motif in p47(phox) Functional studies revealed AngII-induced hypertrophy was absent in EBP50 KOs, and in VSMC overexpressing EBP50, Nox1 gene silencing abolished VSMC hypertrophy. Finally, ex vivo measurement of lumen diameter in mouse resistance arteries exhibited attenuated AngII-induced vasoconstriction in EBP50 KO vs. WT. Taken together, our data identify EBP50 as a previously unidentified regulator of Nox1 and support that it promotes Nox1 activity by binding p47(phox) This interaction is pivotal for agonist-induced smooth muscle ROS, hypertrophy, and vasoconstriction and has implications for ROS-mediated physiological and pathophysiological processes.

Gastric S-nitrosothiol formation drives the antihypertensive effects of oral sodium nitrite and nitrate in a rat model of renovascular hypertension.

Many effects of nitrite and nitrate are attributed to increased circulating concentrations of nitrite, ultimately converted into nitric oxide (NO(•)) in the circulation or in tissues by mechanisms associated with nitrite reductase activity. However, nitrite generates NO(•) , nitrous anhydride, and other nitrosating species at low pH, and these reactions promote S-nitrosothiol formation when nitrites are in the stomach. We hypothesized that the antihypertensive effects of orally administered nitrite or nitrate involve the formation of S-nitrosothiols, and that those effects depend on gastric pH. The chronic effects of oral nitrite or nitrate were studied in two-kidney, one-clip (2K1C) hypertensive rats treated with omeprazole (or vehicle). Oral nitrite lowered blood pressure and increased plasma S-nitrosothiol concentrations independently of circulating nitrite levels. Increasing gastric pH with omeprazole did not affect the increases in plasma nitrite and nitrate levels found after treatment with nitrite. However, treatment with omeprazole severely attenuated the increases in plasma S-nitrosothiol concentrations and completely blunted the antihypertensive effects of nitrite. Confirming these findings, very similar results were found with oral nitrate. To further confirm the role of gastric S-nitrosothiol formation, we studied the effects of oral nitrite in hypertensive rats treated with the glutathione synthase inhibitor buthionine sulfoximine (BSO) to induce partial thiol depletion. BSO treatment attenuated the increases in S-nitrosothiol concentrations and antihypertensive effects of oral nitrite. These data show that gastric S-nitrosothiol formation drives the antihypertensive effects of oral nitrite or nitrate and has major implications, particularly to patients taking proton pump inhibitors.

Consistent antioxidant and antihypertensive effects of oral sodium nitrite in DOCA-salt hypertension.

Hypertension is a common disease that includes oxidative stress as a major feature, and oxidative stress impairs physiological nitric oxide (NO) activity promoting cardiovascular pathophysiological mechanisms. While inorganic nitrite and nitrate are now recognized as relevant sources of NO after their bioactivation by enzymatic and non-enzymatic pathways, thus lowering blood pressure, mounting evidence suggests that sodium nitrite also exerts antioxidant effects. Here we show for the first time that sodium nitrite exerts consistent systemic and vascular antioxidant and antihypertensive effects in the deoxycorticosterone-salt (DOCA-salt) hypertension model. This is particularly important because increased oxidative stress plays a major role in the DOCA-salt hypertension model, which is less dependent on activation of the renin-angiotensin system than other hypertension models. Indeed, antihypertensive effects of oral nitrite were associated with increased plasma nitrite and nitrate concentrations, and completely blunted hypertension-induced increases in plasma 8-isoprostane and lipid peroxide levels, in vascular reactive oxygen species, in vascular NADPH oxidase activity, and in vascular xanthine oxidoreductase activity. Together, these findings provide evidence that the oral administration of sodium nitrite consistently decreases the blood pressure in association with major antioxidant effects in experimental hypertension.

The antihypertensive effects of sodium nitrite are not associated with circulating angiotensin converting enzyme inhibition.

Nitrite-derived nitric oxide (NO) formation exerts antihypertensive effects. Because NO inhibits angiotensin converting enzyme (ACE) activity, we carried a comprehensive series of experiments in rats to test the hypothesis that sodium nitrite exerts antihypertensive effects by inhibiting ACE. We examined whether sodium nitrite (15 mg/kg; or vehicle; by gavage): (I) attenuates the pressor responses to angiotensin I at doses of 0.03, 0.1, 0.3, 1, 3, and 10 µg/kg intravenously; (II) attenuates the acute hypertension induced by L-NAME (100 mg/kg; or vehicle; by gavage); (III) attenuates the chronic hypertension induced by L-NAME (1 g/L in drinking water; or vehicle) administered for 6 weeks; (IV) attenuates the hypertension in the 2 kidney-1 clip (2K1C) chronic hypertension model. Blood samples were collected at the end of each study and plasma angiotensin converting enzyme (ACE) activity was measured with a fluorimetric assay using Hippuryl-His-Leu as substrate. ACE inhibitors were used as positive controls. Plasma nitrite concentrations were measured by ozone-based reductive chemiluminescence. The in vitro effects of sodium nitrite (0, 1, 3, 10, 30, 100 µmol/L) on plasma ACE activity were also determined. We found that sodium nitrite did not affect the pressor responses to angiotensin I. Moreover, while sodium nitrite exerted significant antihypertensive effects in acute and chronic hypertension models, no significant effects on plasma ACE activity were found. In vitro experiments showed no effects of sodium nitrite on plasma ACE activity. This is the first study to demonstrate that the acute and chronic antihypertensive effects of sodium nitrite are not associated with significant inhibition of circulating ACE activity.

Vascular xanthine oxidoreductase contributes to the antihypertensive effects of sodium nitrite in L-NAME hypertension.

Nitrate and nitrite have emerged as an important novel source of nitric oxide (NO). We have previously demonstrated that sodium nitrite is an antihypertensive compound that exerts antioxidant effects in experimental hypertension. These unpredicted antioxidant effects of nitrite raised the question whether the beneficial effects found were caused by its conversion to NO or simply due to reversal of endothelial dysfunction as a consequence of its antioxidant effects. Here, we evaluated the antihypertensive effects of a daily dose of sodium nitrite for 4 weeks in L-NAME-induced hypertension in rats. We studied the effects of nitrite on markers of NO bioavailability, vascular oxidative stress, and expression of xanthine oxidoreductase. Moreover, we tested if xanthine oxidoreductase inhibition could attenuate the acute hypotensive effects of sodium nitrite in L-NAME hypertensive rats. We found that a single pharmacological dose of sodium nitrite exerts antihypertensive effects in L-NAME-induced hypertension. While the beneficial antihypertensive properties of nitrite were associated with increased levels of NO metabolites, hypertension increased vascular xanthine oxidoreductase expression by approximately 40%, with minor increases in vascular superoxide production. The inhibition of xanthine oxidoreductase by oxypurinol attenuated the acute hypotensive effects of nitrite. Taken together, our results show that nitrite exerts antihypertensive effects in L-NAME hypertensive rats and provide evidence that xanthine oxidoreductase plays an important role in this antihypertensive effect.

Hydrogen peroxide modulates phenylephrine-induced contractile response in renal hypertensive rat aorta.

Endothelium-derived factors play an important role in vascular tone control. This study aimed to evaluate how endothelium and reactive oxygen species (ROS) contribute to phenylephrine (PE)-induced contraction in renovascular hypertensive (2K-1C) and normotensive (2K) rats aortas. The effects of the superoxide scavenger Tiron (0.1mM and 1mM) or catalase (30 U/ml, 90 U/ml, 150 U/ml and 300 U/ml) on the PE-induced contraction were evaluated in both intact endothelium (E+) and denuded (E-) aortas. Endothelium removal increased the PE-induced contractions. The maximum contractile response decreased only in 2K-1C rat E+ aorta, and catalase (30 U/ml, 90 U/ml, 150 U/ml) partially reversed this effect. Endothelium increased the basal hydrogen peroxide (H2O2) production in 2K and 2K-1C rats aortas. PE-stimulated H2O2 production was higher in 2K-1C (E+/E-) than in 2K (E+/E-). Inhibition of the enzymes cyclooxygenase, NADPH-oxidase, xanthine-oxidase, and superoxide dismutase reduced the PE-stimulated H2O2 production in 2K-1C rat aorta. The decreased contraction to PE in 2K-1C rat aorta is partially due to endothelial H2O2 production; however, in denuded aorta, it contributes to maintaining the contractile response. Superoxide plays an important role on the PE-induced contraction in 2K rat denuded aorta, whereas in 2K-1C rat aorta, it is H2O2 that plays an important role in this effect.