Nimodipine Protects Vascular and Cognitive Function in an Animal Model of Cerebral Small Vessel Disease.

BACKGROUND: Cerebral small vessel disease is a common cause of vascular cognitive impairment and dementia. There is an urgent need for preventative treatments for vascular cognitive impairment and dementia, and reducing vascular dysfunction may provide a therapeutic route. Here, we investigate whether the chronic administration of nimodipine, a central nervous system-selective dihydropyridine calcium channel blocking agent, protects vascular, metabolic, and cognitive function in an animal model of cerebral small vessel disease, the spontaneously hypertensive stroke-prone rat. METHODS: Male spontaneously hypertensive stroke-prone rats were randomly allocated to receive either a placebo (n=24) or nimodipine (n=24) diet between 3 and 6 months of age. Animals were examined daily for any neurological deficits, and vascular function was assessed in terms of neurovascular and neurometabolic coupling at 3 and 6 months of age, and cerebrovascular reactivity at 6 months of age. Cognitive function was evaluated using the novel object recognition test at 6 months of age. RESULTS: Six untreated control animals were terminated prematurely due to strokes, including one due to seizure, but no treated animals experienced strokes and so had a higher survival (P=0.0088). Vascular function was significantly impaired with disease progression, but nimodipine treatment partially preserved neurovascular coupling and neurometabolic coupling, indicated by larger (P<0.001) and more prompt responses (P<0.01), and less habituation upon repeated stimulation (P<0.01). Also, animals treated with nimodipine showed greater cerebrovascular reactivity, indicated by larger dilation of arterioles (P=0.015) and an increase in blood flow velocity (P=0.001). This protection of vascular and metabolic function achieved by nimodipine treatment was associated with better cognitive function (P<0.001) in the treated animals. CONCLUSIONS: Chronic treatment with nimodipine protects from strokes, and vascular and cognitive deficits in spontaneously hypertensive stroke-prone rat. Nimodipine may provide an effective preventive treatment for stroke and cognitive decline in cerebral small vessel disease.

Upregulation of the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor axis by a combination of Yinyanghuo (Herba Epimedii Brevicornus) and Cheqianzi (Semen Plantaginis) improves erectile function in spontaneously hypertensive rats.

OBJECTIVE: To evaluate the effects of a combination of Yinyanghuo (Herba Epimedii Brevicornus) (HEB) and Cheqianzi (Semen Plantaginis) (SP) on erectile dysfunction caused by essential hypertension in spontaneously hypertensive rats (SHRs), and to elucidate the role of the angiotensin-converting enzyme 2-angiotensin-(1-7)-Mas receptor (ACE2/Ang [1-7]/Mas receptor) axis in this process. METHODS: A total of 24 SHRs were randomly assigned to three groups: SHR-control, low-dose (12.5 g/kg) and high-dose (25 g/kg) HEB+SP (HEBSP). Eight Wistar-Kyoto rats were used as normal controls. HEBSP was administered by oral gavage for 28 d. Erectile function was measured once a week using the Heaton test. After 4 weeks of treatment, the corpus cavernosum was harvested from each rat to measure nitric oxide (NO), nitric oxide synthase (eNOS) and Ang (1-7) levels, as well as ACE2, Mas receptor and neuronal nitric oxide synthase (nNOS) protein expression. RESULTS: After 4 weeks of treatment, HEBSP significantly increased erectile function in the treated group compared with SHR-control group (P < 0.01). Additionally, HEBSP treatment significantly increased cavernosal levels of Ang (1-7), eNOS and NO. Moreover, HEBSP significantly elevated the expression levels of ACE2, Mas receptor and nNOS. These beneficial effects were elevated in the high-dose HEBSP group. CONCLUSION: HEBSP improved erectile function in SHRs by upregulating the ACE2/Ang (1-7)/Mas receptor axis, eNOS and nNOS pathways.

Chemical Characterisation and Antihypertensive Effects of Locular Gel and Serum of Lycopersicum esculentum L. var. "Camone" Tomato in Spontaneously Hypertensive Rats.

Blood pressure control in hypertensive subjects calls for changes in lifestyle, especially diet. Tomato is widely consumed and rich in healthy components (i.e., carotenoids, vitamins and polyphenols). The aim of this study was to evaluate the chemical composition and antihypertensive effects of locular gel reconstituted in serum of green tomatoes of "Camone" variety. Tomato serum and locular gel were chemically characterised. The antihypertensive effects of the locular gel in serum, pure tomatine, and captopril, administered by oral gavage, were investigated for 4 weeks in male spontaneously hypertensive and normotensive rats. Systolic blood pressure and heart rate were monitored using the tail cuff method. Body and heart weight, serum glucose, triglycerides and inflammatory cytokines, aorta thickness and liver metabolising activity were also assessed. Locular gel and serum showed good tomatine and polyphenols content. Significant reductions in blood pressure and heart rate, as well as in inflammatory blood cytokines and aorta thickness, were observed in spontaneously hypertensive rats treated both with locular gel in serum and captopril. No significant effects were observed in normotensive rats. Green tomatoes locular gel and serum, usually discarded during tomato industrial processing, are rich in bioactive compounds (i.e., chlorogenic acid, caffeic acid and rutin, as well as the glycoalkaloids, α-tomatine and dehydrotomatine) that can lower in vivo blood pressure towards healthier values, as observed in spontaneously hypertensive rats.

Electrocardiographic Abnormalities in Hypertension Models

Abstract Background: Hypertensive condition can lead to abnormalities in heart structure and electrical activity. The electrocardiogram (ECG) is a recording of the electrical activity of the heart and widely used to diagnose and detect heart problem. Objective: We conducted a comparative ECG analysis between two hypertension models (L-NAME and SHR) and their controls (Wistar and Wistar-Kyoto) at six and 15 th week of age. Methods: Blood pressure was measured at the end of the 15 th week, and electrocardiography was performed at six and 15 weeks of age in anaesthetized rats. Data normality was confirmed by Kolmogorov-Smirnov test followed by unpaired Student's t-test and the Mann-Whitney for parametric and non-parametric data, respectively. Results are expressed as mean ± SD. The accepted level of significance was set at p < 0.05. Results: L-NAME exhibited prolongation of JT and QT intervals and SHR showed a decrease in heart rate when compared to Wistar-Kyoto and L-NAME. Wistar-Kyoto exhibited short PR interval with increased QRS complex, and only QT prolongation at 15 weeks compared to Wistar. Conclusions: All the hypertension models used in this study featured an increase in blood pressure. However, while SHR showed cardiac dysfunction, L-NAME exhibited changes in ventricular performance. These results may guide future studies on different types and models of hypertension.

Effect of Taichong (LR 3) acupuncture in spontaneously hypertensive rats.

OBJECTIVE: To evaluate the effects of Taichong (LR 3) acupuncture points (acupoints) on the expression of glucose transporter protein 1 (GLUT1) in the hypothalamus of spontaneously hypertensive rats (SHRs) as measured by combined positron emission tomography and computed tomography (PET-CT). METHODS: Spontaneously hypertensive rats (SHR) were divided into model, Taichong (LR 3) acupuncture, and sham groups. Additionally, Tokyo Wistar rats were used as the control group. Changes in blood pressure were recorded in different groups of rats before and after the corresponding treatment. Hematoxylin and eosin (HE) staining was used to study basic morphological changes, and immunohistochemistry was used to determine GLUT1 expression in the hypothalamus. Further, PET-CT was utilized to elucidate the antihypertensive mechanism after acupuncture at the Taichong (LR 3) acupoints. RESULTS: PET-CT indicated activation of the hypothalamus. Measurement of blood pressure showed that acupuncture at the Taichong (LR 3) acupoints lowered blood pressure. HE staining did not show any significant pathological changes, although differences in cell number were observed. Immunohistochemical analysis indicated a GLUT1 downregulation in the SHRs of the Taichong (LR 3) acupuncture group after the treatment. CONCLUSION: Acupuncture at Taichong (LR 3) acupoints lowered blood pressure in SHRs, with possible mechanisms being changes in cell number and GLUT1 expression in the hypothalamus.

Effects of electroacupuncture at Taichong (LR 3) and Baihui (DU 20) on cardiac hypertrophy in rats with spontaneous hypertension.

OBJECTIVE: To investigate the effects of electroacupuncture (EA) at Taichong (LR 3) and Baihui (DU 20) on myocardial hypertrophy in spontaneously hypertensive rats (SHRs). METHODS: Thirty-six SHRs were randomly assigned to model, EA, and Losartan groups, with twelve rats per group. Twelve Wistar Kyoto rats were selected as the normal control group. Systolic blood pressure (SBP) and cardiac function were measured in all rats. Expression levels of factors associated with the phosphoinositide 3-kinase/protein kinase B/mammalian target of rapamycin (PI3K/Akt/mTOR) pathway were evaluated by Western blotting and real-time PCR. Pathological changes of the heart tissue were observed by hematoxylin-eosin staining. RESULTS: After treatment, enhanced SBP was significantly decreased in the EA and Losartan groups compared with the model group (P < 0.01). Echocardiographic and morphological analyses revealed that enhanced end-diastolic interventricular septal thickness and left ventricular posterior wall thickness, as well as ratio of left ventricular weight to body weight were markedly diminished in the EA and Losartan groups (P < 0.01 or P < 0.05), while reduced left ventricular end-diastolic dimension and left ventricular ejection fraction were significantly ameliorated (P < 0.01). Real-time PCR and western blotting analyses showed that the expression levels of PI3K, Akt, and mTOR in SHRs were significantly up-regulated by EA and Losartan (P < 0.01), while the expression levels of PTEN and ANP were down-regulated (P < 0.01). CONCLUSION: EA at Taichong (LR 3) and Baihui (DU 20) inhibited the development of cardiac hypertrophy and improved the cardiac function in SHRs, possibly through regulation of the PI3K/Akt/mTOR signalling pathway.

Behavioural effects of methylphenidate in the spontaneously hypertensive rat model of attention-deficit/hyperactivity disorder: a systematic review and meta-analysis protocol.

INTRODUCTION: Attention-deficit/hyperactivity disorder (ADHD) is a prevalent condition related to several negative outcomes, and its pathophysiology is still poorly understood. The spontaneously hypertensive rats (SHRs) are the most commonly used animal model of ADHD. How ever, its validity, and especially its predictive validity, has been questioned. Therefore, the current protocol discloses the background, aims and methods of a systematic review and meta-analysis of studies reporting the behavioural effects of methylphenidate (MPH), the most commonly prescribed treatment for ADHD, in the SHR. SEARCH STRATEGY: Studies will be identified through a literature search using three different electronic databases: Medline, Embase and Web of Science. There will be no language restrictions. All s tudies that administered MPH to SHR and evaluated locomotion, attention, impulsivity or memory will be included. SCREENING AND ANNOTATION: Studies will be prescreened based on title and abstract, and a full-text review will be performed if necessary. Screening will be performed by two authors, and any disagreement will be discussed with a third author. DATA MANAGEMENT AND REPORTING: Data extraction will be performed by two independent authors according to a standardised form. Studies will be grouped according to the behavioural outcomes reported, and a meta-analysis will be performed for each group. The influence of predefined covariates on the effects of MPH will be evaluated using meta-regression and sensitivity analyses. Data will be reported following PRISMA guidelines.

Downregulation of Plzf Gene Ameliorates Metabolic and Cardiac Traits in the Spontaneously Hypertensive Rat.

The spontaneously hypertensive rat (SHR), one of the most widely used model of essential hypertension, is predisposed to left ventricular hypertrophy, myocardial fibrosis, and metabolic disturbances. Recently, quantitative trait loci influencing blood pressure, left ventricular mass, and heart interstitial fibrosis were genetically isolated within a minimal congenic subline that contains only 7 genes, including mutant Plzf (promyelocytic leukemia zinc finger) candidate gene. To identify Plzf as a quantitative trait gene, we targeted Plzf in the SHR using the transcription activator-like effector nuclease technique and obtained SHR line harboring targeted Plzf gene with a premature stop codon. Because the Plzf targeted allele is semilethal, morphologically normal heterozygous rats were used for metabolic and hemodynamic analyses. SHR-Plzf+/- heterozygotes versus SHR wild-type controls exhibited reduced body weight and relative weight of epididymal fat, lower serum and liver triglycerides and cholesterol, and better glucose tolerance. In addition, SHR-Plzf+/- rats exhibited significantly increased sensitivity of adipose and muscle tissue to insulin action when compared with wild-type controls. Blood pressure was comparable in SHR versus SHR-Plzf+/-; however, there was significant amelioration of cardiomyocyte hypertrophy and cardiac fibrosis in SHR-Plzf+/- rats. Gene expression profiles in the liver and expression of selected genes in the heart revealed differentially expressed genes that play a role in metabolic pathways, PPAR (peroxisome proliferator-activated receptor) signaling, and cell cycle regulation. These results provide evidence for an important role of Plzf in regulation of metabolic and cardiac traits in the rat and suggest a cross talk between cell cycle regulators, metabolism, cardiac hypertrophy, and fibrosis.

Overexpression of Sarcoendoplasmic Reticulum Calcium ATPase 2a Promotes Cardiac Sympathetic Neurotransmission via Abnormal Endoplasmic Reticulum and Mitochondria Ca2+ Regulation.

Reduced cardiomyocyte excitation-contraction coupling and downregulation of the SERCA2a (sarcoendoplasmic reticulum calcium ATPase 2a) is associated with heart failure. This has led to viral transgene upregulation of SERCA2a in cardiomyocytes as a treatment. We hypothesized that SERCA2a gene therapy expressed under a similar promiscuous cytomegalovirus promoter could also affect the cardiac sympathetic neural axis and promote sympathoexcitation. Stellate neurons were isolated from 90 to 120 g male, Sprague-Dawley, Wistar Kyoto, and spontaneously hypertensive rats. Neurons were infected with Ad-mCherry or Ad-mCherry-hATP2Aa (SERCA2a). Intracellular Ca2+ changes were measured using fura-2AM in response to KCl, caffeine, thapsigargin, and carbonylcyanide-p-trifluoromethoxyphenylhydrazine to mobilize intracellular Ca2+ stores. The effect of SERCA2a on neurotransmitter release was measured using [3H]-norepinephrine overflow from 340 to 360 g Sprague-Dawley rat atria in response to right stellate ganglia stimulation. Upregulation of SERCA2a resulted in greater neurotransmitter release in response to stellate stimulation compared with control (empty: 98.7±20.5 cpm, n=7; SERCA: 186.5±28.41 cpm, n=8; P<0.05). In isolated Sprague-Dawley rat stellate neurons, SERCA2a overexpression facilitated greater depolarization-induced Ca2+ transients (empty: 0.64±0.03 au, n=57; SERCA: 0.75±0.03 au, n=68; P<0.05), along with increased endoplasmic reticulum and mitochondria Ca2+ load. Similar results were observed in Wistar Kyoto and age-matched spontaneously hypertensive rats, despite no further increase in endoplasmic reticulum load being observed in the spontaneously hypertensive rat (spontaneously hypertensive rats: empty, 0.16±0.04 au, n=18; SERCA: 0.17±0.02 au, n=25). In conclusion, SERCA2a upregulation in cardiac sympathetic neurons resulted in increased neurotransmission and increased Ca2+ loading into intracellular stores. Whether the increased Ca2+ transient and neurotransmission after SERCA2A overexpression contributes to enhanced sympathoexcitation in heart failure patients remains to be determined.

Tangnaikang improves insulin resistance and ß-cell apoptosis by ameliorating metabolic inflammation in SHR.Cg-Leprcp/NDmcr rats.

OBJECTIVE: To investigate the effects of Tangnaikang (TNK), a mixture of five herbal plant extracts, on inflammation-mediated insulin resistance and B-cell apoptosis in SHR.Cg-Leprcp/NDmcr (SHR-cp) rats. METHODS: Seven-week-old SHR-cp rats were randomly divided into a control (CON) group and a TNK (3.24 g/kg) group. Wistar-Kyoto rats at the same age were used as the normal control group. After 7 weeks of continuous intragastric administration of TNK, the glucose metabolic status and insulin sensitivity of the rats were evaluated by assessing fasting serum glucose (FBG), the oral glucose tolerance test (OGTT), fasting serum insulin (FINS), and the insulin sensitivity index (ISI). Serum tumor necrosis factor-a (TNF-a), interleukin-6 (IL-6), C-reactive protein (CRP) and adiponectin were measured via enzyme-linked immunosorbent assays. Macrophage infiltration and apoptosis in adipose tissues were detected through F4/80 immunohistochemistry and the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Islet morphology and B-cell apoptosis were investigated using double immunofluorescence staining and the TUNEL assay. The expression of cytokine genes in adipose tissue, the liver, and the pancreas was detected in real-time polymerase chain reaction assays. The expression and phosphorylation levels of insulin signaling-, inflammation-, and B-cell survival-related proteins in the liver and pancreas of SHR-cp rats were detected by western blotting. RESULTS: TNK (3.24 g/kg) treatment significantly decreased body weight, FBG and FINS; improved impaired glucose tolerance; increased the ISI; reduced serum levels of TNF-a, CRP and IL-6; and increased serum adiponectin. The mRNA expression of inflammatory markers was markedly reduced in the liver, pancreas, and adipose tissue. F4/80- and TUNEL-positive cells in adipose tissues were decreased, as was the number of TUNEL-positive B-cells. The phosphorylation of c-Jun N-terminal kinase and that of insulin receptor substrate-1 at serines 307 and 1101 was significantly decreased. In the pancreas, the expression of nuclear factor kappa-light chain-enhancer of activated B cells-p65 was significantly decreased, and phosphoinositide 3-kinase and IRS-2 were significantly increased. CONCLUSION: TNK was able to improve insulin resistance and B-cell apoptosis in SHR-cp rats, which might be associated with its ability to relieve the overall and local metabolic inflammatory responses observed in SHR-cp rats.

Efeitos do tratamento crônico com apocinina sobre a resposta vasoconstritora da angiotensina II em ratos espontaneamente hipertensos / Effect of chronic treatment with apocynin on the vasoconstrictor response of angiotensin II in spontaneously hypertensive rats

A enzima NAD(P)H oxidase (NOX) é a principal fonte de espécies reativas de oxigênio (ERO) no sistema cardiovascular e sua atividade e expressão podem ser regulada pela angiotensina (Ang) II. Demonstramos previamente que o tratamento crônico com apocinina, um inibidor de NOX, reduziu a pressão arterial e preveniu o desenvolvimento da disfunção endotelial em SHR. Estes efeitos da apocinina foram associados a redução de geração de ERO e ao aumento da biodisponibilidade de óxido nítrico em células endoteliais de SHR. Dados de nosso laboratório mostraram que o tratamento com apocinina, também reduziu o efeito pressor da Ang II em SHR. A associação entre Ang II, via receptores AT1, e o estresse oxidativo tem sido implicada na patogênese da hipertensão. Levantamos a hipótese que a apocinina, ao alterar a sinalização redox, reduz a expressão de receptores AT1 e a resposta vasoconstritora da Ang II em SHR. Neste estudo, avaliamos o efeito do tratamento crônico com apocinina sobre as respostas contráteis à Ang II em vasos sanguíneos de SHR e os mecanismos envolvidos nestes efeitos, utilizando ensaios bioquímicos, biomoleculares e funcionais. SHR foram tratados com apocinina (30 mg/Kg, v.o.) da 4ª a 10ª semana de vida e ratos Wistar foram utilizados como controle normotenso. Analisamos os efeitos da apocinina na capacidade antioxidante plasmática, expressão de NOX, geração de ERO, níveis de nitrato/ nitrito, expressão de receptores AT1 e AT2, e respostas vasoconstritoras à Ang II em artéria mesentérica e aorta. O tratamento de SHR com apocinina aumentou a capacidade antioxidante plasmática, os níveis de nitrato/nitrito, não alterou a expressão de receptores AT1 ou AT2 em artérias mesentéricas, mas aumentou a expressão de AT2, mas não de AT1, em aorta de SHR. Além disto, o tratamento com apocinina diminuiu a expressão de NOX2 e p47phox e a produção de ERO. O tratamento com apocinina aumentou a modulação do endotélio e/ou da atividade da NOS sobre as respostas vasoconstritoras à Ang II em artérias mesentéricas de SHR, mas não alterou a reatividade de aortas de SHR à Ang II. A menor reatividade de artérias de resistência à Ang II levaria a menor resistência vascular periférica e consequentemente a redução da pressão arterial média e do efeito pressor da Ang II em SHR tratados com apocinina, como observado previamente. O mecanismo de ação da apocinina envolvido neste efeito está associado a importantes alterações redox que determinam uma maior modulação endotelial dependente de NOS das respostas vasoconstritoras da Ang II, mas não envolve alterações na expressão de receptores AT1 em vasos de SHR(AU)

NAD(P)H oxidase (NOX) is the major source of reactive oxygen species (ROS) in the cardiovascular system and its activity and expression could be regulated by angiotensin (Ang) II. We previously demonstrated that chronic treatment with apocynin, a NOX inhibitor, reduced blood pressure and prevented the development of endothelial dysfunction in SHR. These effects of apocynin have been associated with reduced generation of ROS and increased bioavailability of nitric oxide in endothelial cells of SHR. Data from our laboratory showed that treatment with apocynin also reduced the pressor effect of Ang II on SHR. The association between Ang II, via AT1 receptors, and oxidative stress has been implicated in the pathogenesis of hypertension. We hypothesized that apocynin, altering redox signaling, could reduce expression of AT1 receptors and Ang II vasoconstrictor response in SHR. In this study, we evaluated the effect of chronic treatment with apocynin on the contractile responses to Ang II in blood vessels of SHR and the mechanisms involved in the effects of these on biochemical, biomolecular and functional assays. SHR were treated with apocynin (30 mg/kg, p.o.) from the 4 th to the 10th week of life and Wistar rats were used as normotensive control. Analysis of the effects of apocynin on plasma antioxidant capacity, NOX expression, ROS generation, nitrate/ nitrite levels, expression of AT1 and AT2 receptors, and vasoconstrictor responses to Ang II on mesenteric and aortic arteries. Treatment of SHR with apocynin increased plasma antioxidant capacity, nitrate/ nitrite levels, did not alter AT1 or AT2 receptor expression in mesenteric arteries, but increased expression of AT2, but not AT1, in SHR aorta. In addition, treatment with apocynin decreased expression of NOX2 and p47phox and ROS generation. Treatment with apocynin increased endothelium modulation and/or NOS activity on Ang II vasoconstrictor responses in mesenteric arteries of SHR, but did not alter the reactivity to Ang II in aortas of SHR. The lower reactivity of Ang II in resistance arteries would lead to lower peripheral vascular resistance and consequently the reduction of mean arterial pressure and Ang II pressor effect in SHR treated with apocynin, as previously observed. The mechanism of action of the apostate involved in this effect is associated with important redox changes that determine a greater NOS-dependent endothelial modulation of the vasoconstrictor responses of Ang II, but does not involve expression in the expression of AT1 receptors in SHR vessels(AU)

Imunomarcação para TRAP em tecido de reparação óssea de ratos espontaneamente hipertensos (SHR) tratados com Atenolol / Immunostaining for TRAP in bone healing tissue of Spontaneously Hypertensive Rats (SHR) treated with Atenolol

Introdução: A hipertensão arterial tem sido um dos maiores problemas de saúde no mundo, com grandes alterações para as doenças cardiovasculares e renais. O tecido ósseo tem função importante no suporte, proteção e locomoção e está sob o controle de fatores sistêmicos como hormônios e fatores locais, entre eles os fatores de crescimento e citocinas. A Fosfatase Ácida Tartarato Resistente (TRAP) é uma enzima que faz parte da família das fosfatases ácidas e apresenta localização intracelular; mais especificamente dentro do compartimento lisossomal de osteoclasto, macrófagos e células dendríticas, tem sido utilizada como um marcador histoquímico da atividade osteoclástica. Objetivos: Avaliar a expressão da proteína TRAP em alvéolos dentários de ratos hipertensos (SHR) e normotensos tratados ou não com atenolol. Métodos: Neste estudo foram utilizados 4 grupos de ratos sendo: 1) W (wistar sem tratamento), 2) WT (wistar tratado com atenolol), 3) S (SHR sem tratamento) e 4) ST (SHR tratado com atenolol), submetidos a exodontia do incisivo superior direito, com eutanásia no 7º, 14º, 21 e 28º dia pós-operatório. A análise dos mecanismos biológicos envolvidos no processo de reparo alveolar foi obtida pela análise da expressão de proteínas TRAP por meio da técnica de imunoistoquímica. Os resultados foram analisados pela média e erro padrão da média e aplicado o teste paramétrico ANOVA, com pos-test de Tukey para avaliar os períodos dentro de cada grupo e entre os grupos, sendo consideradas as diferenças significativas quando p<0,05. Resultados: Os resultados mostraram que a marcação TRAP aumenta em alvéolo dentais de ratos Wistar durante todos os períodos pós ­ operatórios. A marcação TRAP aumenta apenas ao 14o nos dias de reparação alveolar em alvéolo dental de SHR não tratados. O atenolol não altera o processo de reparo alveolar em ratos Wistar, porém o atenolol promoveu a redução da marcação de TRAP em SHR ao 14º dia. Conclusão: A hipertensão aumenta a expressão da proteína TRAP no 14o dia pós-cirúrgico de reparação alveolar e o atenolol promove redução da marcação aumentada de TRAP ao 14º dia pós-cirúrgico em alvéolos de SHR(AU)

Introduction: Arterial hypertension has been one of the world's biggest health problems, with considerable alterations for cardiovascular and renal diseases. The bone tissue has an important role in support, protection and locomotion and is controlled by systemic factors like hormones and local factors, such as growth factors and cytokines. The Tartrate-resistant Acid Phosphatase (TRAP) is an enzyme that belongs to the Acid Phosphatases family and has an intracellular location, more specifically inside the lysosomal compartment of osteoclasts, macrophages and dendritic cells. It has been used as a histochemical marker of the osteoclast activity. Objectives: Evaluate TRAP protein's expression in the dental alveoli of normotensive and hypertensive rats (SHR) treated or not treated with Atenolol. Methods: In this study, four groups of rats were used: 1) W (with no treatment), 2) WT (wistar treated with Atenolol), 3) S (SHR without treatment) and 4) ST (SHR treated with Atenolol), all of which underwent exodontia of the upper right incisor with euthanasia on the 7th, 14th, 21st and 28th day after the operation. The analysis of the biological mechanisms involved in the process of alveolar repair was obtained by the expression of TRAP proteins in the alveolar process through an immunohistochemistry technique. The results were analyzed through the average and its standard error. The parametric test ANOVA was applied with Tukey's posttest were applied to evaluate the periods within each group and between the groups, considering the significant differences when p< 0,05. Results: The results demonstrated that TRAP staining increases in the dental alveoli of Wistar rats during all the post-surgical periods. TRAP staining increases only on the 14th day of alveolar recovery in the dental alveoli of non-treated SHR. Atenolol does not change the process of alveolar repair in Wistar rats, but Atenolol promoted the reduction of TRAP staining among SHR on the 14th day. Conclusion: Hypertension increases the expression of TRAP proteins on the 14th alveolar recovery postsurgical day and Atenolol promotes the reduction of the increased TRAP staining on the 14th postsurgical day in SHR's alveoli(AU)

Contribution of Orexin to the Neurogenic Hypertension in BPH/2J Mice.

BPH/2J mice are a genetic model of hypertension associated with an overactive sympathetic nervous system. Orexin is a neuropeptide which influences sympathetic activity and blood pressure. Orexin precursor mRNA expression is greater in hypothalamic tissue of BPH/2J compared with normotensive BPN/3J mice. To determine whether enhanced orexinergic signaling contributes to the hypertension, BPH/2J and BPN/3J mice were preimplanted with radiotelemetry probes to compare blood pressure 1 hour before and 5 hours after administration of almorexant, an orexin receptor antagonist. Mid frequency mean arterial pressure power and the depressor response to ganglion blockade were also used as indicators of sympathetic nervous system activity. Administration of almorexant at 100 (IP) and 300 mg/kg (oral) in BPH/2J mice during the dark-active period (2 hours after lights off) markedly reduced blood pressure (-16.1 ± 1.6 and -11.0 ± 1.1 mm Hg, respectively;P<0.001 compared with vehicle). However, when almorexant (100 mg/kg, IP) was administered during the light-inactive period (5 hours before lights off) no reduction from baseline was observed (P=0.64). The same dose of almorexant in BPN/3J mice had no effect on blood pressure during the dark (P=0.79) or light periods (P=0.24). Almorexant attenuated the depressor response to ganglion blockade (P=0.018) and reduced the mid frequency mean arterial pressure power in BPH/2J mice (P<0.001), but not BPN/3J mice (P=0.70). Immunohistochemical labeling revealed that BPH/2J mice have 29% more orexin neurons than BPN/3J mice which are preferentially located in the lateral hypothalamus. The results suggest that enhanced orexinergic signaling contributes to sympathetic overactivity and hypertension during the dark period in BPH/2J mice.

Genetic Variation in Renal Expression of Folate Receptor 1 (Folr1) Gene Predisposes Spontaneously Hypertensive Rats to Metabolic Syndrome.

Metabolism of homocysteine and other sulfur amino acids is closely associated with metabolism of folates. In this study, we analyzed the possible role of folates and sulfur amino acids in the development of features of the metabolic syndrome in the BXH/HXB recombinant inbred strains derived from the spontaneously hypertensive rat (SHR) and Brown Norway progenitors. We mapped a quantitative trait locus for cysteine concentrations to a region of chromosome 1 that contains a cis-acting expression quantitative trait locus regulating mRNA levels of folate receptor 1 (Folr1) in the kidney. Sequence analysis revealed a deletion variant in the Folr1 promoter region of the SHR. Transfection studies demonstrated that the SHR-promoter region of Folr1 is less effective in driving luciferase reporter gene expression than the Brown Norway promoter region of Folr1. Results in the SHR.BN-chr.1 congenic strain confirmed that the SHR variant in Folr1 cosegregates with markedly reduced renal expression of Folr1 and renal folate reabsorption, decreased serum levels of folate, increased serum levels of cysteine and homocysteine, increased adiposity, ectopic fat accumulation in liver and muscle, reduced muscle insulin sensitivity, and increased blood pressure. Transgenic rescue experiments performed by expressing a Folr1 transgene in the SHR ameliorated most of the metabolic disturbances. These findings are consistent with the hypothesis that inherited variation in the expression of Folr1 in the kidney influences the development of the metabolic syndrome and constitutes a previously unrecognized genetic mechanism that may contribute to increased risk for diabetes mellitus and cardiovascular disease.

Efeito vasorelaxante do doador de óxido nítrico [Ru(terpy)(bdq)NO]3+ (TERPY) em artéria de resistência e sua interação com a óxido nítrico sintase endotelial (eNOS) de Ratos Espontaneamente Hipertensos (SHR) / Vasorelaxation effect of nitric oxide donor [Ru(terpy)(bdq)NO]3+ (TERPY) on resistance artery and its interaction with endothelial nitric oxide synthase (eNOS) of Spontaneously Hypertensive Rats (SHR)

O TERPY promove efeito hipotensor de maior magnitude em ratos hipertensos (SHR e 2R-1C) do que em ratos normotensos (Wistar e 2R). Foi demonstrado anteriormente que o endotélio prejudica o efeito vasodilatador do TERPY em aorta de Wistar. No entanto, observamos que o endotélio melhora os efeitos vasodilatadores do TERPY em aorta de SHR. Vasos sanguíneos de menor calibre, tais como as artérias de resistência, estão associadas ao controle da resitência vascular periférica e da pressão arterial. Nossa hipótese é que o TERPY induz relaxamento nas artérias mesentéricas de resistência em SHR e que as células endoteliais modulam positivamente o efeito do TERPY nestes vasos sanguíneos. Portanto, o nosso objetivo foi avaliar o efeito vasodilatador do TERPY em anéis com e sem endotélio de artéria mesentérica de ratos SHR, o seu mecanismo de relaxamento e a participação da NOS sobre esse efeito. e a Nossos resultados mostraram que o TERPY induziu um efeito vasodilatador dependente da concentração em anéis de artérias mesentéricas (2º e 3º ramos) de SHR e de ratos Wistar. A potência do TERPY foi maior em anéis intactos do que em anéis sem endotélio em artérias mesentéricas de SHR, mas em Wistar o endotélio prejudicou o efeito do TERPY. Nas artérias mesentéricas sem endotélio de SHR, o efeito do TERPY é dependente da atividade da guanilato ciclase solúvel e de canais para potássio. Nas artérias mesentéricas intactas de SHR, o efeito de TERPY depende da atividade de eNOS, mas não é dependente das atividades de nNOS, iNOS ou da via da ciclooxigenase. O TERPY promove a fosforilação da eNOS nos resíduos de serina1177 e aumenta a concentração de óxido nítrico em células endoteliais isoladas de artérias mesentéricas de SHR. Nossos resultados mostraram que a guanilato ciclase solúvel, os canais para potássio e a eNOS estão envolvidos no efeito vasodilatador estimulado pelo TERPY nas artérias de resistência mesentérica de SHR. Numa segunda parte deste estudo, avaliamos o mecanismo de ação de TERPY e seu efeito sobre a atividade da eNOS em células endoteliais. As células HUVEC, WT-HEK e HEK-eNOS foram tratadas com TERPY em diferentes tempos (0 a 60 minutos). Foram analisados por Western blotting o efeito do TERPY sobre a fosforilação de eNOS, monômero e dímero da eNOS e sobre monômero e oligômero de caveolina-1. Também foi avaliado o efeito do TERPY na interação eNOS/Cav-1 através de co-imunoprecipitação. As alterações induzidas pelo TERPY sobre as concentrações de espécies reativas de oxigênio e peroxinitrito em células endoteliais foram medidas usando sonda DHE e biossensor 7-CBA, respectivamente. A concentração de óxido nítrico (NO) foi avaliada por sonda DAF-FM e sensor Cooper. O TERPY promoveu desacoplamento e disfunção da eNOS, dependente de BH4. A desestabilização dos oligômeros da caveolina-1 foi induzida pelo TERPY. Consequentemente, o TERPY reduziu a interação eNOS/Cav-1 e promoveu ativação da eNOS. Nossos resultados mostraram que a atividade da eNOS pode ser regulada de duas maneiras diferentes pelo TERPY. O TERPY promove desacoplamento e fosforilação da eNOS, promovendo uma estratégia diferente para a regulação da atividade desta enzima. As moléculas químicas ou biológicas como o TERPY que regulam a atividade da eNOS e aumentam a produção e a biodisponibilidade de NO teriam ações terapêuticas importantes para o tratamento de doenças vasculares associadas a hipertensão(AU)

TERPY promotes a hypotensive effect with greater magnitude in hypertensive rats (SHR and 2K-1C) than in normotensive rats (Wistar and 2K). Previously, it was demonstrated that endothelium impairs vasodilatory effect of TERPY in Wistar aorta. However, we observed that endothelium improves the vasodilatory effect of TERPY in SHR aorta. Smaller blood vessels, such as mesenteric arteries, are associated with the control of peripheral vascular resistance and blood pressure. We hypothesized that TERPY induces relaxation on mesenteric resistance arteries in SHR and endothelial cells modulate positively the TERPY's effect on these blood vessels. Therefore, our goal was to evaluate the vasodilator effect of TERPY in rings with and without endothelium of mesenteric arteries in SHR, the mechanism of relaxation and the participation of NOS on this effect. Our results show TERPY induced a concentration-dependent vasodilator effect in mesenteric arteries (2nd and 3 rd branches) rings from SHR and Wistar. The potency of TERPY was higher in intact than in denuded rings from SHR, but in Wistar, endothelium impair the TERPY's effect. In denuded mesenteric arteries from SHR, the relaxation effect induced by TERPY is dependent of soluble guanylate cyclase and activation of potassium channel. However, in intact mesenteric arteries from SHR, TERPY´s effect is modulated by eNOS activity, but it is not dependent of nNOS, iNOS or cyclooxygenase pathway activities. TERPY promotes eNOS3 Ser1177 phosphorylation and increases nitric oxide concentration in isolated endothelial cells of mesenteric arteries from SHR. Together, our results showed that soluble guanylate cyclase, potassium channels, and eNOS are involved in the vasodilator effect of TERPY in mesenteric resistance arteries from SHR. In a second part of this study, we aimed to evaluate the mechanism of action of TERPY and its effect on eNOS activity in endothelial cells. HUVEC, WT-HEK and HEK-eNOS cells were treated with TERPY at different times (0 to 60 minutes). Were analyzed by western blotting the TERPY`s effect on eNOS monomer, dimer and phosphorylation and on monomer and oligomer of caveolin-1. It was also evaluated the effect of TERPY in the interaction between eNOS/Cav-1 through co-immunoprecipitation. Alterations induced by TERPY on reactive oxygen species and peroxynitrite concentrations in endothelial cells were measured by using DHE probe and biosensor 7-CBA, respectively. Nitric oxide fluorescence was assessed by DAF-FM probe and Cooper sensor. TERPY promoted eNOS uncoupling and eNOS dysfunction, which is BH4-dependent. Caveolin-1 oligomers destabilization was induced by TERPY. Consequently, TERPY reduced eNOS/Cav-1 interaction and promoted eNOS activation. Our results show that eNOS activity can be regulated in two different ways by TERPY, leading to eNOS uncoupling and leading to eNOS phosphorylation, promoting a strategy for eNOS regulation. Chemical or biological molecules as TERPY that regulates eNOS activity and increase NO production and bioavailability are potential therapeutic drugs for the treatment of vascular diseases associated with hypertension(AU)

Effects of Fosinopril on Oxidative Stress and Vascular Function in Experimental Rats With Spontaneous Hypertension / 中国循环杂志

Objective: To explore the effects of fosinopril on oxidative stress and vascular function in experimental rats with spontaneous hypertension. Methods: The rats were divided into 3 groups: Control group, with normal healthy rats (n=15), Spontaneous hypertension (SH) group (n=15), SH rats received intragastric administration of normal saline and Treatment group (n=15), SH rats received intragastric administration of fosinopril 10mg/(kg?d). All animals were treated for 7 weeks. Caudal artery systolic blood pressure (SBP) was measured at each week. blood levels of superoxide dismutase (SOD), reactive oxygen species (ROS), malonaldehyde (MDA) and NO2-/NO3- were determined in different groups respectively after 7 weeks. Moreover, thoracic aorta was taken to examine its diastolic reactive rate by acetylcholine (Ach)/sodium nitroprusside (SNP) induction. Results: From the 1st week until the end of experiment, compared with SH group, Treatment group had decreased SBP,P<0.05. With 7 weeks treatment, compared with Control group, SH group had decreased SOD activity, while increased protein levels of MDA and ROS, allP<0.05; compared with SH group, Treatment group showed elevated SOD activity (P=0.010), while reduced protein levels of MDA (P=0.021) and ROS (P=0.009). Compared with Control group, SH group had the lower content of NO2-/NO3-(P<0.001); both SH group and Treatment group had decreased diastolic rates by Ach/SNP induction,P<0.05. Compared with SH group, Treatment group presented the higher content of NO2-/NO3- and higher diastolic rate by Ach induction, allP<0.001. Conclusion: Fosinopril could improve vascular diastolic function via anti-oxidative stress in experimental SH rats, which might be one of its anti-hypertensive mechanisms.

Antihypertension and cardio-protective effect of Zusanli and Taichong in spontaneously ;hypertensive rats / 国际中医中药杂志

Objective This study aims to explore antihypertension and heart protective effect of acupuncture on SHR rats through the observation of blood pressure, cardiac ultrasound and pathology examination of SHR rats after needling the Zusanli (ST 36) and Taichong (LR 3). Methods A total of 14 SHR rats (10 weeks) were randomly divided into two groups:6 for model group and 8 for acupuncture group, another 6 SD rats (10 weeks) were used as the control group. SHR rats in the acupuncture group were fixed in the holder, and then they exposed both lower limbs for needling both sides Zusanli (ST 36) and Taichong (LR 3), and then they retained needles for 20 minutes per time with four weeks. The other two groups were fixed in the holder without needling. Blood pressure was examined each week. LVSs, LVDd, LVPWs, LVPWd were measured and recorded by cardiac ultrasound in the day after the whole course of acupuncture. LVM, LVMI, RWT were calculated. The hearts of rats were dissected and fixed in formalin for heart pathology detection after doing the cardiac ultrasound. Results After acupuncture treatment, compared with model group, the systolic blood pressure (SBP) of the third week (178.38 ± 9.47 mmHg vs. 190.00 ± 13.90 mmHg) and the fourth week (167.96 ± 23.47 mmHg vs. 195.47 ± 11.36 mmHg) of acupuncture group significantly decreased (P<0.01). The diastolic pressure (DBP) of the third week (139.33 ± 13.20 mmHg vs. 159.56 ± 12.89 mmHg) and the fourth week (132.92 ± 18.02 mmHg vs. 165.61 ± 13.36 mmHg) of acupuncture group significantly decreased (P<0.01). The LVSs (0.96 ± 0.07 vs. 1.28 ± 0.24), LVPWs (1.15 ± 0.08 vs. 1.68 ± 0.19) of the acupuncture group were significantly lower than those of the model group (P<0.01). The LVM (0.51 ± 0.12 vs. 0.84 ± 0.17) and LVMI (14.96 ± 1.53 vs. 23.65 ± 5.04) of acupuncture group were significantly lower than those of the model group (P<0.01). Histopathologic examination of the heart of the model group showed chronic inflammatory granulation tissue hyperplasia and fibrosis in myocardial outer membrane, but the acupuncture group showed no obvious changes in the heart tissue. Conclusions Acupuncture treatment on Zusanli (ST 36) and Taichong (LR 3) could effectively control the left ventricular hypertrophy by decreasing the SBP and DBP , prevent cardiac remodeling, and protect myocardial cells.

Effect of Intravenous Infusion of Vasostatin-2 on Hemodynamics in Experimental Rats With Spontaneous Hypertension / 中国循环杂志

Objective: To observe the effect of the intravenous infusion of vasostatin-2 (VS-2) on hemodynamics in experimental rats with spontaneous hypertension (SH). Methods: A total of 36 (14-16) weeks male SH rats with the mean body weight at (160-250) g were randomly divided into 6 groups:①Control group, the rats received normal saline (100μl/kg),②Catestatin (20μg/kg) group,③VS-2 (5μg/kg) group,④VS-2 (10μg/kg) group,⑤VS-2 (20μg/kg) group and⑥VS-2 (40μg/kg) group. n=6 in each group. The average blood pressure (BP), heart rate (HR) and barorelfex sensitivity (BRS) were monitored and compared upon VS-2 treatment and between VS-2 and catestatin treatments in conscious and freelance rats. Results: Compared with prior treatment, VS-2 (20μg/kg) and VS-2 (40μg/kg) could obviously decrease the HR, BP and BRS in SH rats. In VS-2 (20μg/kg) group, HR by bpm was (341.3 ± 19.3) vs (365.5 ± 25.5), BP by mmHg was (133.0 ± 8.9) vs (147.5 ± 11.2) and BRS by ms/mmHg was (0.52 ± 0.18) vs (0.37 ± 0.12);in VS-2 (40μg/kg) group, HR was (348.8 ± 30.8) vs (374.5 ± 34.8), BP was (131.5 ± 9.3) vs (151.7 ± 10.8) and BRS was (0.53 ± 0.05) vs (0.38 ± 0.03), all P0.05. Conclusion: Intravenous infusion of VS-2 may obviously affect HR, BP and BRS in experimental SH rats;compared with the same dosage of catestatin, VS-2 had the weaker reduction of HR, BP and BRS.