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2.
Int. j. cardiovasc. sci. (Impr.) ; 35(2): 161-171, Mar.-Apr. 2022. tab, graf
Article in English | LILACS | ID: biblio-1364975

ABSTRACT

Abstract Background: There are divergences in the literature regarding the experimental model (Wistar-WIS or Wistar Kyoto-WKY) to be used as a Spontaneously Hypertensive Rat (SHR) control. The characterization of these models in terms of cardiovascular parameters provides researchers with important tools at the time of selection and application in scientific research. Objective: The aim of this study was to evaluate the use of WIS and WKY as a Spontaneously Hypertensive Rat (SHR) control by assessing the long-term behavior of blood pressure and cardiac structure and function in these strains. Methods: To this end, WIS, WKY, and SHR underwent longitudinal experiments. Blood pressure and body mass were measured every two weeks from the 8th to the 72nd. Echocardiographic analysis was performed in all groups with 16, 48, and 72 weeks of life. After having applied the normality test, the Two-Way ANOVA of repeated measures followed by the Tukey post hoc test was used. A significance level of 5% was established. Results: The WIS group showed higher body mass (p<0.05), while the WKY and SHR presented higher body mass variation over time (p<0.05). SHR exhibited increased values of systolic, diastolic, and mean blood pressure when compared to WKY and WIS, whereas the WKY generally showed higher values than WIS (p<0.05). Regarding the cardiac function, SHR showed reduced values, while the WKY presented an early decrease when compared to WIS with aging (p<0.05). Conclusion: WIS is a more suitable normotensive control for SHR than WKY in experiments to test blood pressure and cardiac structure and function.


Subject(s)
Animals , Male , Rats , Arterial Pressure/physiology , Heart/anatomy & histology , Heart/physiology , Hypertension/physiopathology , Rats, Inbred SHR , Rats, Inbred WKY , Body Weight , Echocardiography , Longitudinal Studies , Rats, Wistar , Disease Models, Animal
3.
Journal of Integrative Medicine ; (12): 432-441, 2022.
Article in English | WPRIM | ID: wpr-939903

ABSTRACT

OBJECTIVE@#To investigate the influence of electroacupuncture (EA) on ghrelin and the phosphoinositide 3-kinase/protein kinase B/endothelial nitric oxide synthase (PI3K/Akt/eNOS) signaling pathway in spontaneously hypertensive rats (SHRs).@*METHODS@#Eight Wistar-Kyoto rats were used as the healthy blood pressure (BP) control (normal group), and 32 SHRs were randomized into model group, EA group, EA plus ghrelin group (EA + G group), and EA plus PF04628935 group (a potent ghrelin receptor blocker; EA + P group) using a random number table. Rats in the normal group and model group did not receive treatment, but were immobilized for 20 min per day, 5 times a week, for 4 continuous weeks. SHRs in the EA group, EA + G group and EA + P group were immobilized and given EA treatment in 20 min sessions, 5 times per week, for 4 weeks. Additionally, 1 h before EA, SHRs in the EA + G group and EA + P group were intraperitoneally injected with ghrelin or PF04628935, respectively, for 4 weeks. The tail-cuff method was used to measure BP. After the 4-week intervention, the rats were sacrificed by cervical dislocation, and pathological morphology of the abdominal aorta was observed using hematoxylin-eosin (HE) staining. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of ghrelin, nitric oxide (NO), endothelin-1 (ET-1) and thromboxane A2 (TXA2) in the serum. Isolated thoracic aortic ring experiment was performed to evaluate vasorelaxation. Western blot was used to measure the expression of PI3K, Akt, phosphorylated Akt (p-Akt) and eNOS proteins in the abdominal aorta. Further, quantitative real-time polymerase chain reaction (qRT-PCR) was conducted to measure the relative levels of mRNA expression for PI3K, Akt and eNOS in the abdominal aorta.@*RESULTS@#EA significantly reduced the systolic BP (SBP) and diastolic BP (DBP) (P < 0.05). HE staining showed that EA improved the morphology of the vascular endothelium to some extent. Results of ELISA indicated that higher concentrations of ghrelin and NO, and lower concentrations of ET-1 and TXA2 were presented in the EA group (P < 0.05). The isolated thoracic aortic ring experiment demonstrated that the vasodilation capacity of the thoracic aorta increased in the EA group. Results of Western blot and qRT-PCR showed that EA increased the abundance of PI3K, p-Akt/Akt and eNOS proteins, as well as expression levels of PI3K, Akt and eNOS mRNAs (P < 0.05). In the EA + G group, SBP and DBP decreased (P < 0.05), ghrelin concentrations increased (P < 0.05), and the concentrations of ET-1 and TXA2 decreased (P < 0.05), relative to the EA group. In addition, the levels of PI3K and eNOS proteins, the p-Akt/Akt ratio, and the expression of PI3K, Akt and eNOS mRNAs increased significantly in the EA + G group (P < 0.05), while PF04628935 reversed these effects.@*CONCLUSION@#EA effectively reduced BP and protected the vascular endothelium, and these effects may be linked to promoting the release of ghrelin and activation of the PI3K/Akt/eNOS signaling pathway.


Subject(s)
Animals , Electroacupuncture , Ghrelin/pharmacology , Nitric Oxide/metabolism , Nitric Oxide Synthase Type III/pharmacology , Phosphatidylinositol 3-Kinase/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Proto-Oncogene Proteins c-akt/pharmacology , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Signal Transduction
4.
Article in Chinese | WPRIM | ID: wpr-939509

ABSTRACT

OBJECTIVE@#To observe the effect of electroacupuncture (EA) at "Neiguan" (PC 6) on cardiac function of ventriculus sinister in rats with spontaneously hypertensive (SHR), and to explore the mediation effect of endothelin-1 (ET-1)/endothelial nitric oxide synthase (eNOS).@*METHODS@#Six 12-week-old male Wistar Kyoto (WKY) rats were taken as the normal group. Eighteen 12-week-old SHR were randomly divided into a model group, an EA group and a sham EA group, 6 rats in each group. The rats in the EA group were treated with EA (disperse-dense wave, 2 Hz/15 Hz in frequency, 1 mA in current intensity) at "Neiguan" (PC 6), 30 min each time, once a day for 8 weeks. The rats in the sham EA group were treated with superficial needling at "Neiguan" (PC 6) with no electrical stimulation applied. After treatment, the left ventricular ejection fraction (LVEF) and left ventricular fractional shortening (LVFS) were tested by echocardiographic analysis. The left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), heart rate (HR), the maximum rate of increase/decrease of left ventricular pressure (±dp/dtmax) were detected. The serum content of ET-1 was detected by ELISA. Western blot was used to evaluate the expression of ETAR, eNOS in myocardial tissue of left ventricular.@*RESULTS@#Compared with the normal group, LVEF, LVFS, +dp/dtmax/LVSP and -dp/dtmax/LVSP were decreased (P<0.01, P<0.05), while LVSP, LVEDP, +dp/dtmax and -dp/dtmax were increased (P<0.01) in the model group. Compared with the model group, LVEF, LVFS, +dp/dtmax/LVSP and -dp/dtmax/LVSP were increased (P<0.01, P<0.05), and LVSP and LVEDP were decreased (P<0.01) in the EA group. Compared with the normal group, the serum content of ET-1 and the expression of ETAR in myocardial tissue were increased (P<0.01), whereas expression of eNOS was decreased (P<0.01) in the model group. Compared with the model group, the serum content of ET-1 and the expression of ETAR in myocardial tissue were decreased (P<0.05), whereas expression of eNOS was increased (P<0.05) in the EA group.@*CONCLUSION@#EA intervention may alleviate hypertensive cardiac function damage by up-regulating the expression of eNOS protein in myocardial tissue, down-regulating the serum content of ET-1 and the expression of ETAR protein in myocardial tissue.


Subject(s)
Animals , Electroacupuncture , Endothelin-1/genetics , Heart Diseases , Hypertension/therapy , Male , Nitric Oxide Synthase Type III/genetics , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Stroke Volume , Ventricular Function, Left
5.
Article in Chinese | WPRIM | ID: wpr-936376

ABSTRACT

OBJECTIVE@#To explore the role of interleukin-17A (IL-17A) in renal epithelial- mesenchymal transition (EMT) in essential hypertensive nephropathy.@*METHODS@#Four-week-old spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats (control group) were both randomized into 4 groups (n=5) for observation at 4, 6, 10 and 30 weeks of age. Blood pressure of the rats was monitored using a noninvasive tail artery blood pressure measurement instrument. The percentage of Th17 cells in the splenocytes was analyzed using flow cytometry. The mRNA and protein expression levels of IL-17A, iNOS, Arg-1, E-cadherin, and α-SMA in the kidneys of the rats were detected using RT-PCR and immunohistochemical staining, respectively, and plasma levels of IL-17A were regularly detected using ELISA.@*RESULTS@#At the age of 6 weeks, the SHRs began to show significantly higher blood pressure with greater Th17 cell percentage in the splenocytes and high renal expression and plasma level of IL-17A than WKY rats (P < 0.05 or P < 0.01). At 30 weeks, renal expression of E-cadherin mRNA and protein was significantly lower and the expression of Arg-1 mRNA and protein was significantly higher in SHR than in WKY rats (P < 0.01). Compared with the WKY rats, the SHRs showed significantly higher mRNA and protein expressions of iNOS at 6 and 10 weeks (P < 0.05 or 0.01) and higher α-SMA mRNA and protein expressions since 10 weeks of age (P < 0.05 or 0.01). In SHRs older than 10 weeks, renal IL-17A mRNA and protein expression levels were negatively correlated with those of E-cadherin (r=-0.731, P < 0.05; r=-0.827, P < 0.01) and positively correlated with those of α-SMA (r=0.658, P < 0.05; r=0.968, P < 0.01).@*CONCLUSION@#IL-17A is closely correlated with the progression of renal EMT in SHR and plays its role possibly by mediating M1/M2 polarization of renal infiltrating macrophages.


Subject(s)
Animals , Blood Pressure , Cadherins/metabolism , Epithelial-Mesenchymal Transition , Hypertension , Interleukin-17/metabolism , Kidney , RNA, Messenger/metabolism , Rats , Rats, Inbred SHR , Rats, Inbred WKY
6.
Int. j. cardiovasc. sci. (Impr.) ; 33(4): 321-328, July-Aug. 2020. tab, graf
Article in English | LILACS | ID: biblio-1134389

ABSTRACT

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.


Subject(s)
Animals , Male , Rats , Electrocardiography/methods , Hypertension/complications , Rats, Inbred WKY , Rats, Wistar , NG-Nitroarginine Methyl Ester/adverse effects
7.
Braz. j. med. biol. res ; 53(12): e9615, 2020. tab, graf
Article in English | LILACS, ColecionaSUS | ID: biblio-1132513

ABSTRACT

The sympathetic nervous system (SNS) plays a fundamental role in the pathophysiology of cardiovascular diseases, including primary arterial hypertension. In this study, we aimed to investigate whether the expression of the rate-limiting enzyme in catecholamine synthesis, tyrosine hydroxylase (TH), and the β2-adrenergic receptor (β2-AR) in immune cells from peripheral blood, reflect central SNS activity in spontaneously hypertensive rats (SHR). TH expression in the lower brainstem and adrenal glands and β2-AR expression in the lower brainstem were analyzed by western blot analyses. In the leukocytes, TH and β2-AR expression was evaluated by flow cytometry before and after chronic treatment with the centrally-acting sympathoinhibitory drug clonidine. Western blot analyses showed increased TH and β2-AR expression in the lower brainstem and increased TH in adrenal glands from SHR compared to normotensive Wistar Kyoto rats (WKY). Lower brainstem from SHR treated with clonidine presented reduced TH and β2-AR levels, and adrenal glands had decreased TH expression compared to SHR treated with vehicle. Flow cytometry showed that the percentage of leukocytes that express β2-AR is higher in SHR than in WKY. However, the percentage of leukocytes that expressed TH was higher in WKY than in SHR. Moreover, chronic treatment with clonidine normalized the levels of TH and β2-AR in leukocytes from SHR to similar levels of those of WKY. Our study demonstrated that the percentage of leukocytes expressing TH and β2-AR was altered in arterial hypertension and can be modulated by central sympathetic inhibition with clonidine treatment.


Subject(s)
Animals , Rats , Hypertension/drug therapy , Rats, Inbred SHR , Rats, Inbred WKY , Sympathetic Nervous System , Tyrosine 3-Monooxygenase , Blood Pressure , Receptors, Adrenergic, beta-2 , Leukocytes
8.
Psychiatry Investigation ; : 558-564, 2019.
Article in English | WPRIM | ID: wpr-760953

ABSTRACT

OBJECTIVE: Synaptic vesicle mobilization and neurite outgrowth regulation molecules were examined in modulation of effects of methylphenidate (MPH) in Spontaneous Hypertensive Rats (SHRs), a model for attention-deficit hyperactivity disorder (ADHD). METHODS: We compared the changes in the protein expression level of Cyclin dependent kinase 5 (Cdk5) and molecular substrates of Cdk5; tropomyosin receptor kinase B (TrkB), syntaxin 1A (STX1A) and synaptosomal-associated protein 25 (SNAP25). Comparisons were made in prefrontal cortex of vehicle (distilled water i.p. for 7 days)-treated SHRs, vehicle-treated Wistar Kyoto Rats (WKYs) and MPH (2 mg/kg i.p. for 7 days) treated SHRs. RESULTS: The Cdk5 level of vehicle-treated SHRs was significantly decreased compared to the Cdk5 level of vehicle-treated WKY rats, but was restored to the expression level of vehicle-treated WKYs in MPH-treated SHR. The ratio of p25/p35 was significantly decreased in MPH-treated SHR compared to vehicle-treated SHR. Moreover, TrkB, STX1A and SNAP25 of vehicle-treated SHRs were significantly decreased compared to vehicle-treated WKY rats, but were restored to the expression level of vehicle-treated WKYs in MPH-treated SHR. CONCLUSION: The results show that Cdk5, TrkB, STX1A, and SNAP25 were involved in the modulation of MPH effects in prefrontal cortex of SHRs and play important role in treatment of ADHD.


Subject(s)
Animals , Cyclin-Dependent Kinase 5 , Methylphenidate , Neurites , Phosphotransferases , Prefrontal Cortex , Rats , Rats, Inbred WKY , Soluble N-Ethylmaleimide-Sensitive Factor Attachment Proteins , Synaptic Vesicles , Synaptosomal-Associated Protein 25 , Syntaxin 1 , Tropomyosin , Water
9.
Acta Physiologica Sinica ; (6): 395-404, 2019.
Article in Chinese | WPRIM | ID: wpr-777174

ABSTRACT

The present study was designed to examine whether Ramipril (an inhibitor of angiotensin-converting enzyme) affected spontaneous hypertension-induced injury of cerebral artery by regulating connexin 43 (Cx43) expression. Wistar-Kyoto (WKY) and spontaneously hypertensive rats (SHR) were randomly divided into WKY, WKY + Ramipril, SHR, and SHR + Ramipril groups (n = 8). The arterial pressure was monitored by the tail-cuff method, and vascular function in basilar arteries was examined by pressure myography. Hematoxylin-eosin (HE) staining was used to show vascular remodeling. The expression and distribution of Cx43 was determined by using immunofluorescence and immunohistochemistry analysis. The protein and mRNA levels of Cx43 were examined by Western blot and real-time PCR analysis, respectively. The results showed that chronic Ramipril treatment significantly attenuated blood pressure elevation (P < 0.01, n = 8) and blood vessel wall thickness in SHR (P < 0.01, n = 8). The cerebral artery contraction rate in the SHR group was higher than that in the WKY group (P < 0.05, n = 8). The cerebral artery contraction rate in the SHR + Ramipril group was lower than that in the SHR group (P < 0.05, n = 8). Pretreatment with 2-APB (Cx43 non-specific blocker) or Gap26 (Cx43 specific blocker) significantly decreased the vasoconstriction rate, while pretreatment with AAP10 (Cx43 non-specific agonist) significantly increased the vasoconstriction in the SHR + Ramipril group (P < 0.05, n = 8). In addition, the expression of Cx43 mRNA and protein in cerebral arteries of SHR group was higher than that of WKY group (P < 0.05, n = 8). The mRNA and protein expression of Cx43 in cerebral arteries of SHR + Ramipril group was significantly lower than that of SHR group (P < 0.05, n = 8). These results suggest that Ramipril can down-regulate the expression of Cx43 mRNA and protein in cerebral arterial cells of SHR, lower blood pressure, promote vasodilation, and improve arterial damage and vascular dysfunction caused by hypertension.


Subject(s)
Animals , Blood Pressure , Cerebral Arteries , Metabolism , Connexin 43 , Metabolism , Hypertension , Drug Therapy , Ramipril , Pharmacology , Random Allocation , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Vascular Remodeling
10.
Acta Physiologica Sinica ; (6): 505-513, 2019.
Article in English | WPRIM | ID: wpr-777161

ABSTRACT

Activation of peripheral respiratory chemoreceptors provokes respiratory and cardiovascular reflexes, providing a novel understanding of pathogenic mechanism of hypertension. Here we hypothesize that activation of peripheral respiratory chemoreceptors by hypoxia causes enhanced cardiorespiratory activity in conscious spontaneously hypertensive rats (SHRs). Using whole body plethysmography in combination with radio telemetry, pulmonary ventilation, arterial blood pressure and heart rate were examined in SHRs and Wistar-Kyoto (WKY) rats. We found that exposure to hypoxia induced greater increases in tidal volume and minute ventilation volume in SHRs compared to WKY rats. In addition, hypoxia caused a robust increase in arterial blood pressure and heart rate in SHRs relative to WKY counterparts. After carotid body denervation, the hypoxic ventilatory response was significantly decreased in both SHRs and WKY rats, but without significant difference between the two strains; moreover, the differences of arterial blood pressure and heart rate changes during hypoxic exposure were statistically insignificant between SHRs and WKY rats. It is concluded that hypoxia remarkably potentiates cardiorespiratory activity in the SHRs, suggesting an enhanced sensitivity of carotid bodies to hypoxia.


Subject(s)
Animals , Blood Pressure , Heart Rate , Hypertension , Hypoxia , Rats , Rats, Inbred SHR , Rats, Inbred WKY
11.
Article in Chinese | WPRIM | ID: wpr-774567

ABSTRACT

The aim of this study was to observe the effect of baicalin on the growth state of attention deficit hyperactivity disorder animal model and its regulation on Ca MKⅡand ERK1/2.In the present study,a total of 40 SHR rats were randomly divided into model group,methylphenidate hydrochloride group,and low,medium,and high dose baicalin groups,with 8 rats in each group.Eight WKYrats were selected as a normal control group.The methylphenidate hydrochloride group(0.07 g·L~(-1))and the low(3.33 g·L~(-1)),medium(6.67 g·L~(-1)),and high dose(10 g·L~(-1))baicalin groups received corresponding drugs by gavage administration according to the body weight(0.015 m L·g~(-1)),while the normal group and the model group received the same volume of normal saline by gavage.Thegavage administration lasted for 4 weeks,twice a day.The body weight of the rats and the amount of remaining feed were weighed daily,and the growth state of the rats was statistically evaluated weekly.Percoll density gradient centrifugation was used to prepare brain synaptosomes and an electron microscope was used to observe their structures.The Ca MKⅡand ERK1/2 protein and mRNA expression levels were detected with Western blot and Real-time PCR methods,respectively.RESULTS: showed that baicalin did not affect the normal eating and weight gain of rats,and the weight gain of rats was even more significant than that in the normal group(P<0.05).In the study of its effects on Ca MKⅡand ERK1/2 protein expression in rat synaptosomes,the expression of both proteins in each drug-administered group was higher than that in the model group(P<0.05);besides,the expression levels of Ca MKⅡand ERK1/2 protein were significantly increased in both baicalin high dose group and the methylphenidate hydrochloride group(P<0.05).The relative expression of Ca MKⅡand ERK1/2 mRNA in synaptosome was detected by PCR.The results showed that medium and high doses of baicalin and methylphenidate hydrochloride significantly increased the relative expression of Ca MKⅡand ERK1/2 mRNA in synaptosomes of SHR rats(P<0.05).In conclusion,baicalin does not affect the normal growth and development of SHR rats,so it is safe for administration.Both baicalin and methylphenidate hydrochloride could up-regulate the relative expression of Ca MKⅡand ERK1/2 in mRNA and protein,and the pharmacodynamic stability of baicalin is in a dose-dependent manner to certain extent.


Subject(s)
Animals , Attention Deficit Disorder with Hyperactivity , Disease Models, Animal , Flavonoids , Intracellular Signaling Peptides and Proteins , MAP Kinase Signaling System , Protein Serine-Threonine Kinases , Rats , Rats, Inbred SHR , Rats, Inbred WKY
12.
Braz. j. med. biol. res ; 52(6): e8009, 2019. graf
Article in English | LILACS | ID: biblio-1001539

ABSTRACT

The progression of myocardial injury secondary to hypertension is a complex process related to a series of physiological and molecular factors including oxidative stress. This study aimed to investigate whether moderate-intensity exercise (MIE) could improve cardiac function and oxidative stress in spontaneously hypertensive rats (SHRs). Eight-week-old male SHRs and age-matched male Wistar-Kyoto rats were randomly assigned to exercise training (treadmill running at a speed of 20 m/min for 1 h continuously) or kept sedentary for 16 weeks. Cardiac function was monitored by polygraph; cardiac mitochondrial structure was observed by scanning electron microscope; tissue free radical production was measured using dihydroethidium staining. Expression levels of SIRT3 and SOD2 protein were measured by western blot, and cardiac antioxidants were assessed by assay kits. MIE improved the cardiac function of SHRs by decreasing left ventricular systolic pressure (LVSP), and first derivation of LVP (+LVdP/dtmax and −LVdP/dtmax). In addition, exercise-induced beneficial effects in SHRs were mediated by decreasing damage to myocardial mitochondrial morphology, decreasing production of reactive oxygen species, increasing glutathione level, decreasing oxidized glutathione level, increasing expression of SIRT3/SOD2, and increasing activity of superoxide dismutase. Exercise training in SHRs improved cardiac function by inhibiting hypertension-induced myocardial mitochondrial damage and attenuating oxidative stresses, offering new insights into prevention and treatment of hypertension.


Subject(s)
Animals , Male , Rats , Blood Pressure/physiology , Oxidative Stress/physiology , Hypertension/physiopathology , Mitochondria, Heart/physiology , Cardiomyopathies/prevention & control , Physical Conditioning, Animal/physiology , Rats, Inbred SHR , Rats, Inbred WKY , Superoxide Dismutase/physiology , Microscopy, Electron, Scanning , Disease Models, Animal , Cardiomyopathies/physiopathology , Cardiomyopathies/diagnostic imaging
13.
Arq. bras. cardiol ; 110(3): 263-269, Mar. 2018. tab, graf
Article in English | LILACS | ID: biblio-888040

ABSTRACT

Abstract Background: Alterations in the structure of resistance vessels contribute to elevated systemic vascular resistance in hypertension and are linked to sympathetic hyperactivity and related lesions in target organs. Objective: To assess the effects of exercise training on hemodynamic and autonomic parameters, as well as splenic arteriolar damages in male Wistar Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR). Methods: Normotensive sedentary (WKYS) and trained (WKYT) rats, and hypertensive sedentary (SHRS) and trained (SHRT) rats were included in this study. After 9 weeks of experimental protocol (swimming training or sedentary control), arterial pressure (AP) and heart rate (HR) were recorded in freely moving rats. We assessed the autonomic control of the heart by sympathetic and vagal autonomic blockade. Morphometric analyses of arterioles were performed in spleen tissues. The statistical significance level was set at p < 0.05. Results: Resting bradycardia was observed in both trained groups (WKYT: 328.0 ± 7.3 bpm; SHRT: 337.0 ± 5.2 bpm) compared with their respective sedentary groups (WKYS: 353.2 ± 8.5 bpm; SHRS: 412.1 ± 10.4 bpm; p < 0.001). Exercise training attenuated mean AP only in SHRT (125.9 ± 6.2 mmHg) vs. SHRS (182.5 ± 4.2 mmHg, p < 0.001). The WKYT showed a higher vagal effect (∆HR: 79.0 ± 2.3 bpm) compared with WKYS (∆HR: 67.4 ± 1.7 bpm; p < 0.05). Chronic exercise decreased sympathetic effects on SHRT (∆HR: -62.8 ± 2.8 bpm) in comparison with SHRS (∆HR: -99.8 ± 9.2 bpm; p = 0.005). The wall thickness of splenic arterioles in SHR was reduced by training (332.1 ± 16.0 µm2 in SHRT vs. 502.7 ± 36.3 µm2 in SHRS; p < 0.05). Conclusions: Exercise training attenuates sympathetic activity and AP in SHR, which may be contributing to the morphological improvement of the splenic arterioles.


Resumo Fundamento: Alterações na estrutura dos vasos de resistência contribuem para elevar a resistência vascular sistêmica na hipertensão, estando ligadas à hiperatividade simpática e lesões em órgãos-alvo. Objetivo: Avaliar os efeitos do treinamento físico nos parâmetros hemodinâmicos e autônomos, assim como as lesões arteriolares esplênica em ratos machos Wistar Kyoto (WKY) e espontaneamente hipertensos (SHR). Métodos: Ratos normotensos sedentários (WKYS) e treinados (WKYT), e ratos hipertensos sedentários (SHRS) e treinados (SHRT) foram incluídos neste estudo. Após nove semanas de aplicação do protocolo experimental (treinamento de natação ou controle sedentário), registraram-se a pressão arterial (PA) e a frequência cardíaca (FC) dos ratos em movimento livre. Avaliamos o controle autônomo do coração através de bloqueio autônomo simpático e vagal. Análises morfométricas das arteríolas esplênicas foram realizadas. Adotou-se o nível de significado estatístico de p < 0,05. Resultados: Observou-se bradicardia de repouso nos dois grupos treinados (WKYT: 328,0 ± 7,3 bpm; SHRT: 337,0 ± 5,2 bpm) em comparação aos seus respectivos grupos sedentários (WKYS: 353,2 ± 8,5 bpm; SHRS: 412,1 ± 10,4 bpm; p < 0,001). O treinamento físico atenuou a PA média apenas no grupo SHRT (125,9 ± 6,2 mmHg vs. 182,5 ± 4,2 mmHg no SHRS; p < 0,001). O grupo WKYT mostrou maior efeito vagal (∆FC: 79,0 ± 2,3 bpm) em comparação ao grupo WKYS (∆FC: 67,4 ± 1,7 bpm; p < 0,05). Exercício crônico diminuiu os efeitos simpáticos em SHRT (∆FC: -62.8 ± 2.8 bpm) em comparação a SHRS (∆FC: -99,8 ± 9,2 bpm; p = 0,005). A espessura da parede das arteríolas esplênicas nos SHR foi reduzida pelo treinamento (332,1 ± 16,0 µm2 nos SHRT vs. 502,7 ± 36,3 µm2 nos SHRS; p < 0,05). Conclusões: O treinamento físico atenua a atividade simpática e a PA em SHR, o que pode contribuir para melhorar a morfologia das arteríolas esplênicas.


Subject(s)
Animals , Male , Physical Conditioning, Animal/physiology , Splenic Artery/physiopathology , Splenic Artery/pathology , Sympathetic Nervous System/physiopathology , Vascular Resistance/physiology , Arterial Pressure/physiology , Hypertension/physiopathology , Physical Conditioning, Animal/methods , Arterioles/physiopathology , Rats, Inbred SHR , Rats, Inbred WKY , Reference Values , Time Factors , Reproducibility of Results , Treatment Outcome , Exercise Therapy/methods , Heart Rate/physiology , Hypertension/therapy
14.
Article in English | WPRIM | ID: wpr-715441

ABSTRACT

OBJECTIVE: Whether blood-brain barrier (BBB) disruption induced by chronic spontaneous hypertension is associated with beta-amyloid (Aβ) accumulation in the brain remains poorly understood. The purpose of this study was to investigate the relationship between BBB disruption and Aβ influx and accumulation in the brain of aged rats with chronic spontaneous hypertension. MATERIALS AND METHODS: Five aged spontaneously hypertensive rats (SHRs) and five age-matched normotensive Wistar-Kyoto (WKY) rats were studied. The volume transfer constant (Ktrans) obtained from dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) was used to evaluate BBB permeability in the hippocampus and cortex in vivo. The BBB tight junctions, immunoglobulin G (IgG), Aβ, and amyloid precursor protein (APP) in the hippocampus and cortex were examined with immunohistochemistry. RESULTS: As compared with WKY rats, the Ktrans values in the hippocampus and cortex of the SHRs increased remarkably (0.316 ± 0.027 min−1 vs. 0.084 ± 0.017 min−1, p < 0.001 for hippocampus; 0.302 ± 0.072 min−1 vs. 0.052 ± 0.047 min−1, p < 0.001 for cortex). Dramatic occludin and zonula occludens-1 losses were detected in the hippocampus and cortex of SHRs, and obvious IgG exudation was found there. Dramatic Aβ accumulation was found and limited to the area surrounding the BBB, without extension to other parenchyma regions in the hippocampus and cortex of aged SHRs. Alternatively, differences in APP expression in the hippocampus and cortex were not significant. CONCLUSION: Blood-brain barrier disruption is associated with Aβ influx and accumulation in the brain of aged rats with chronic spontaneous hypertension. DCE-MRI can be used as an effective method to investigated BBB damage.


Subject(s)
Alzheimer Disease , Amyloid , Animals , Blood-Brain Barrier , Brain , Hippocampus , Hypertension , Immunoglobulin G , Immunohistochemistry , Magnetic Resonance Imaging , Methods , Occludin , Permeability , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Tight Junctions
15.
Article in Chinese | WPRIM | ID: wpr-773783

ABSTRACT

OBJECTIVES@#Investigate the influence of benazepril and amlodipine on the expression of secretin (PZ) and somatostatin (SS) in spontaneously hypertensive rats (SHR).@*METHODS@#Forty-five SHRs (14 weeks old, male) were randomly assigned into 3 groups (=15):SHR group, Benazepril group (which was given benazepril 0.90 mg·kg·d) and Amlodipine group (SHRs were given amlodipine 0.45 mg· kg·d), taking WistarKyoto(WKY) as normal control (=15), meanwhile, rats in SHR group and WKY group were given the same volume of distilled water. After 8 weeks of intervention, the expression of protein and mRNA of PZ in duodenum and SS in sinuses ventriculi was detected by enzyme-linked immunoassay and RT-PCR.@*RESULTS@#After 8 weeks of intervention, compared with the WKY group, the expression of protein and mRNA of PZ in duodenum and SS in sinuses ventriculi was increased significantly in SHR group (<0. 05). Compared with SHR group, the expression of PZ in duodenum and SS in sinuses ventriculi was decreased significantly in Benazepril group and Amlodipine group (<0.05). Compared with Benazepril group, in Amlodipine group the expression of PZ mRNA in duodenum and SS mRNA in sinuses ventriculi was decreased more significantly (<0.05).@*CONCLUSIONS@#The regulation disorder of PZ in duodenum and SS in sinuses ventriculi exists in SHR. The antihypertensive effect of benazepril and amlodipine may be realized by regulating the expression of PZ and SS, while the regulation of amlodipine is more obvious than benazepril.


Subject(s)
Amlodipine , Pharmacology , Animals , Antihypertensive Agents , Pharmacology , Benzazepines , Pharmacology , Blood Pressure , Hypertension , Drug Therapy , Male , Random Allocation , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Secretin , Metabolism , Somatostatin , Metabolism
16.
Braz. j. med. biol. res ; 51(11): e7338, 2018. tab, graf
Article in English | LILACS | ID: biblio-951725

ABSTRACT

Hypertensive renal damage generally occurs during the middle and late stages of hypertension, which is typically characterized by proteinuria and renal inflammation. Captopril, an angiotensin-converting enzyme (ACE) inhibitor, has been widely used for therapy of arterial hypertension and cardiovascular diseases. However, the protective effects of captopril on hypertension-induced organ damage remain elusive. The present study was designed to explore the renoprotective action of captopril in spontaneously hypertensive rats (SHR). The 6-week-old male SHR and age-matched Wistar-Kyoto rats were randomized into long-term captopril-treated (34 mg/kg) and vehicle-treated groups. The results showed that in SHR there was obvious renal injury characterized by the increased levels of urine albumin, total protein, serum creatinine, blood urea nitrogen, renal inflammation manifested by the increased mRNA and protein expression of inflammatory factors including tumor necrosis factor-α, interleukin (IL)-1β, IL-6, and inducible nitric oxide synthase, and enhanced nuclear factor-κB (NF-κB) activation. Captopril treatment could lower blood pressure, improve renal injury, and suppress renal inflammation and NF-κB activation in SHR rats. In conclusion, captopril ameliorates renal injury and inflammation in SHR possibly via inactivation of NF-κB signaling.


Subject(s)
Animals , Male , Rats , Proteinuria/prevention & control , Angiotensin-Converting Enzyme Inhibitors/therapeutic use , Captopril/therapeutic use , NF-kappa B/adverse effects , Hypertension/drug therapy , Nephritis/prevention & control , Antihypertensive Agents/therapeutic use , Proteinuria/etiology , Rats, Inbred SHR , Rats, Inbred WKY , Signal Transduction , Hypertension/complications , Nephritis/etiology
17.
Acta cir. bras ; 32(5): 388-395, May 2017. tab, graf
Article in English | LILACS | ID: biblio-837711

ABSTRACT

Abstract Purpose: To evaluate DNA damage levels in pregnant rats undergoing a treadmill exercise program. Methods: Wistar Kyoto rats were allocated into two groups (n= 5 animals/group): non-exercise and exercise. The pregnant rats were underwent an exercise protocol on a treadmill throughout pregnancy. Exercise intensity was set at 50% of maximal capacity during maximal exercise testing performed before mating. Body weight, blood pressure and glucose levels, and triglyceride concentration were measured during pregnancy. At day 10 post-natal, the animals were euthanized and maternal blood samples were collected for DNA damage. Results: Blood pressure and glucose levels and biochemical measurements showed no significant differences. Increased DNA damage levels were found in exercise group compared to those of non-exercise group (p<0.05). Conclusion: The exercise intensity protocol used in the study might have been exhaustive leading to maternal increased DNA damage levels, demonstrating the relevance of an adequate protocol of physical exercise.


Subject(s)
Animals , Female , DNA Damage/physiology , Exercise Test/adverse effects , Physical Conditioning, Animal , Rats, Inbred WKY , Blood Glucose/analysis , Blood Pressure/physiology , Body Weight/physiology , Pregnancy , Random Allocation , Comet Assay/methods , Models, Animal , Exercise Test/standards , Fetal Viability/physiology , Animals, Newborn/physiology
18.
Article in English | WPRIM | ID: wpr-812076

ABSTRACT

Angiotensin II (Ang II) is involved in endothelium injury during the development of hypertension. Tribulus terrestris (TT) is used to treat hypertension, arteriosclerosis, and post-stroke syndrome in China. The present study aimed to determine the effects of aqueous TT extracts on endothelial injury in spontaneously hypertensive rats (SHRs) and its protective effects against Ang II-induced injury in human umbilical vein endothelial cells (HUVECs). SHRs were administered intragastrically with TT (17.2 or 8.6 g·kg·d) for 6 weeks, using valsartan (13.5 mg·kg·d) as positive control. Blood pressure, heart rate, endothelial morphology of the thoracic aorta, serum levels of Ang II, endothelin-1 (ET-1), superoxide dismutase (SOD) and malonaldehyde (MDA) were measured. The endothelial injury of HUVECs was induced by 2 × 10 mol·L Ang II. Cell Apoptosisapoptosis, intracellular reactive oxygen species (ROS) was assessed. Endothelial nitric oxide synthase (eNOS), ET-1, SOD, and MDA in the cell culture supernatant and cell migration were assayed. The expression of hypertension-linked genes and proteins were analyzed. TT decreased systolic pressure, diastolic pressure, mean arterial pressure and heart rate, improved endothelial integrity of thoracic aorta, and decreased serum leptin, Ang II, ET-1, NPY, and Hcy, while increased NO in SHRs. TT suppressed Ang II-induced HUVEC proliferation and apoptosis and prolonged the survival, and increased cell migration. TT regulated the ROS, and decreased mRNA expression of Akt1, JAK2, PI3Kα, Erk2, FAK, and NF-κB p65 and protein expression of Erk2, FAK, and NF-κB p65. In conclusion, TT demonstrated anti-hypertensive and endothelial protective effects by regulating Erk2, FAK and NF-κB p65.


Subject(s)
Angiotensin II , Metabolism , Animals , Antihypertensive Agents , Apoptosis , Blood Pressure , Endothelium, Vascular , Metabolism , Human Umbilical Vein Endothelial Cells , Humans , Hypertension , Drug Therapy , Genetics , Metabolism , Male , NF-kappa B , Genetics , Metabolism , Nitric Oxide Synthase Type III , Genetics , Metabolism , Oxidative Stress , Plant Extracts , Proto-Oncogene Proteins c-akt , Genetics , Metabolism , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Reactive Oxygen Species , Metabolism , Tribulus , Chemistry
19.
Article in Chinese | WPRIM | ID: wpr-297244

ABSTRACT

<p><b>OBJECTIVE</b>To study the effect of baicalin on synaptosomal adenosine triphosphatase (ATPase) and lactate dehydrogenase (LDH) and its regulatory effect on the adenylate cyclase (AC)/cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA) signaling pathway in rats with attention deficit hyperactivity disorder (ADHD).</p><p><b>METHODS</b>A total of 40 SHR rats were randomly divided into five groups: ADHD model, methylphenidate hydrochloride treatment (0.07 mg/mL), and low-dose (3.33 mg/mL), medium-dose (6.67 mg/mL), and high-dose (10 mg/mL) baicalin treatment (n=8 each). Eight WKY rats were selected as normal control group. Percoll density gradient centrifugation was used to prepare brain synaptosomes and an electron microscope was used to observe their structure. Colorimetry was used to measure the activities of ATPase and LDH in synaptosomes. ELISA was used to measure the content of AC, cAMP, and PKA.</p><p><b>RESULTS</b>Compared with the normal control group, the ADHD model group had a significant reduction in the ATPase activity, a significant increase in the LDH activity, and significant reductions in the content of AC, cAMP, and PKA (P<0.05). Compared with the ADHD model group, the methylphenidate hydrochloride group and the medium- and high-dose baicalin groups had a significant increase in the ATPase activity (P<0.05), a significant reduction in the LDH activity (P<0.05), and significant increases in the content of AC, cAMP, and PKA (P<0.05). Compared with the methylphenidate hydrochloride group, the high-dose baicalin group had significantly greater changes in these indices (P<0.05). Compared with the low-dose baicalin group, the high-dose baicalin group had a significant increase in the ATPase activity (P<0.05); the medium- and high-dose baicalin groups had a significant reduction in the LDH activity (P<0.05) and significant increases in the content of AC, cAMP, and PKA (P<0.05). Compared with the medium-dose baicalin group, the high-dose baicalin group had a significant increase in the ATPase activity (P<0.05).</p><p><b>CONCLUSIONS</b>Both methylphenidate hydrochloride and baicalin can improve synaptosomal ATPase and LDH activities in rats with ADHD. The effect of baicalin is dose-dependent, and high-dose baicalin has a significantly greater effect than methylphenidate hydrochloride. Baicalin exerts its therapeutic effect possibly by upregulating the AC/cAMP/PKA signaling pathway.</p>


Subject(s)
Adenosine Triphosphatases , Metabolism , Adenylyl Cyclases , Physiology , Animals , Attention Deficit Disorder with Hyperactivity , Drug Therapy , Cyclic AMP , Physiology , Cyclic AMP-Dependent Protein Kinases , Physiology , Flavonoids , Pharmacology , Therapeutic Uses , L-Lactate Dehydrogenase , Metabolism , Rats , Rats, Inbred SHR , Rats, Inbred WKY , Signal Transduction , Synaptosomes , Chemistry
20.
Article in Chinese | WPRIM | ID: wpr-297182

ABSTRACT

<p><b>OBJECTIVE</b>To investigate the effect of baicalin on the behavioral characteristics of rats with attention deficit hyperactivity disorder (ADHD), and to provide a basis for further research on baicalin in the treatment of ADHD.</p><p><b>METHODS</b>A total of 40 SHR rats were randomly divided into model group, methylphenidate hydrochloride (MPH) group, and low-, medium-, and high-dose baicalin groups, with 8 rats in each group. Eight WKY rats were selected as normal control group. The rats in the MPH group (0.07 mg/mL) and the low- (3.33 mg/mL), medium- (6.67 mg/mL), and high-dose (10 mg/mL) baicalin groups were given the corresponding drugs (1.5 mL/100 g) by gavage twice a day, and those in the normal control group and the model group were given an equal volume of normal saline by gavage twice a day. The course of treatment was 4 weeks for all groups. The open field test was performed to observe total moving distance and average moving speed on day 0 of experiment and at 7, 14, 21, and 28 days after gavage and to evaluate the control effects of drugs on hyperactivity and impulsive behavior. The Morris water maze test was used to observe the latency, time spent in the target quadrant, and number of platform crossings and to evaluate the effects of drugs on attention.</p><p><b>RESULTS</b>The open field test showed that the model group and the drug treatment groups had a significantly longer total moving distance and a significantly higher average moving speed than the normal control group on day 0 (P<0.05). On day 7, the MPH group had significant reductions in total moving distance and average moving speed compared with the model group (P<0.05). On day 14, the MPH group and the high-dose baicalin group had significant reductions in total moving distance and average moving speed compared with the model group (P<0.05). The data on days 21 and 28 showed that compared with the model group, the low-, medium-, and high-dose baicalin groups had gradual reductions in total moving distance and average moving speed (P<0.05). The water maze test showed that compared with the model group, the MPH group and the medium- and high-dose baicalin groups had a significantly longer time spent in the target quadrant (P<0.05), and the MPH group and the high-dose baicalin group had a significantly higher proportion of the moving distance in the target quadrant in total moving distance (P<0.05). The high-dose baicalin group had the highest number of platform crossings among all groups (P<0.05).</p><p><b>CONCLUSIONS</b>Both baicalin and MPH can regulate the motor ability and learning and memory abilities of SHR rats with ADHD and thus control the core symptoms of ADHD, i.e., hyperactivity, impulsive behavior, and inattention. Baicalin exerts its effect in a dose-dependent manner, and high-dose baicalin has the most significant effect, but compared with MPH, it needs a longer time to play its therapeutic effect.</p>


Subject(s)
Animals , Attention Deficit Disorder with Hyperactivity , Drug Therapy , Psychology , Behavior, Animal , Dose-Response Relationship, Drug , Flavonoids , Therapeutic Uses , Male , Maze Learning , Motor Activity , Rats , Rats, Inbred SHR , Rats, Inbred WKY
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