Chronic intermittent hypobaric hypoxia (CIHH) is known to have an anti-hypertensive effect, which might be related to modulation of the baroreflex in rats with renal vascular hypertension (RVH). In this study, RVH was induced by the 2-kidney-1-clip method (2K1C) in adult male Sprague-Dawley rats. The rats were then treated with hypobaric hypoxia simulating 5000 m altitude for 6 h/day for 28 days. The arterial blood pressure (ABP), heart rate (HR), and renal sympathetic nerve activity (RSNA) were measured before and after microinjection of L-arginine into the nucleus tractus solitarii (NTS) in anesthetized rats. Evoked excitatory postsynaptic currents (eEPSCs) and spontaneous EPSCs (sEPSCs) were recorded in anterogradely-labeled NTS neurons receiving baroreceptor afferents. We measured the protein expression of neuronal nitric oxide synthase (nNOS) and endothelial NOS (eNOS) in the NTS. The results showed that the ABP in RVH rats was significantly lower after CIHH treatment. The inhibition of ABP, HR, and RSNA induced by L-arginine was less in RVH rats than in sham rats, and greater in the CIHH-treated RVH rats than the untreated RVH rats. The eEPSC amplitude in NTS neurons receiving baroreceptor afferents was lower in the RVH rats than in the sham rats and recovered after CIHH. The protein expression of nNOS and eNOS in the NTS was lower in the RVH rats than in the sham rats and this decrease was reversed by CIHH. In short, CIHH treatment decreases ABP in RVH rats via up-regulating NOS expression in the NTS.
Animals ; Baroreflex ; physiology ; Blood Pressure ; drug effects ; Hypertension ; metabolism ; Hypoxia ; chemically induced ; Kidney ; drug effects ; metabolism ; Male ; Nitric Oxide Synthase Type I ; drug effects ; metabolism ; Rats, Sprague-Dawley ; Solitary Nucleus ; metabolism

Metformin (MET), an antidiabetic agent, also has antioxidative effects in metabolic-related hypertension. This study was designed to determine whether MET has anti-hypertensive effects in salt-sensitive hypertensive rats by inhibiting oxidative stress in the hypothalamic paraventricular nucleus (PVN). Salt-sensitive rats received a high-salt (HS) diet to induce hypertension, or a normal-salt (NS) diet as control. At the same time, they received intracerebroventricular (ICV) infusion of MET or vehicle for 6 weeks. We found that HS rats had higher oxidative stress levels and mean arterial pressure (MAP) than NS rats. ICV infusion of MET attenuated MAP and reduced plasma norepinephrine levels in HS rats. It also decreased reactive oxygen species and the expression of subunits of NAD(P)H oxidase, improved the superoxide dismutase activity, reduced components of the renin-angiotensin system, and altered neurotransmitters in the PVN. Our findings suggest that central MET administration lowers MAP in salt-sensitive hypertension via attenuating oxidative stress, inhibiting the renin-angiotensin system, and restoring the balance between excitatory and inhibitory neurotransmitters in the PVN.
Animals ; Antioxidants ; therapeutic use ; Arterial Pressure ; drug effects ; Hypertension ; chemically induced ; drug therapy ; Infusions, Intraventricular ; Male ; Metformin ; administration & dosage ; pharmacology ; Neurotransmitter Agents ; metabolism ; Oxidative Stress ; drug effects ; Paraventricular Hypothalamic Nucleus ; drug effects ; Rats ; Reactive Oxygen Species ; metabolism ; Sodium Chloride, Dietary ; pharmacology

Angiotensin (Ang)-(1-7) is an important biologically-active peptide of the renin-angiotensin system. This study was designed to determine whether inhibition of Ang-(1-7) in the hypothalamic paraventricular nucleus (PVN) attenuates sympathetic activity and elevates blood pressure by modulating pro-inflammatory cytokines (PICs) and oxidative stress in the PVN in salt-induced hypertension. Rats were fed either a high-salt (8% NaCl) or a normal salt diet (0.3% NaCl) for 10 weeks, followed by bilateral microinjections of the Ang-(1-7) antagonist A-779 or vehicle into the PVN. We found that the mean arterial pressure (MAP), renal sympathetic nerve activity (RSNA), and plasma norepinephrine (NE) were significantly increased in salt-induced hypertensive rats. The high-salt diet also resulted in higher levels of the PICs interleukin-6, interleukin-1beta, tumor necrosis factor alpha, and monocyte chemotactic protein-1, as well as higher gp91 expression and superoxide production in the PVN. Microinjection of A-779 (3 nmol/50 nL) into the bilateral PVN of hypertensive rats not only attenuated MAP, RSNA, and NE, but also decreased the PICs and oxidative stress in the PVN. These results suggest that the increased MAP and sympathetic activity in salt-induced hypertension can be suppressed by blockade of endogenous Ang-(1-7) in the PVN, through modulation of PICs and oxidative stress.
Angiotensin I ; antagonists & inhibitors ; metabolism ; Animals ; Antioxidants ; pharmacology ; Blood Pressure ; drug effects ; Hypertension ; chemically induced ; drug therapy ; Male ; Oxidative Stress ; drug effects ; Paraventricular Hypothalamic Nucleus ; drug effects ; Peptide Fragments ; antagonists & inhibitors ; metabolism ; Rats, Sprague-Dawley ; Reactive Oxygen Species ; metabolism ; Sodium Chloride, Dietary ; pharmacology

Fructose intake has increased dramatically over the past century and the upward trend has continued until recently. Increasing evidence suggests that the excessive intake of fructose induces salt-sensitive hypertension. While the underlying mechanism is complex, the kidney likely plays a major role. This review will highlight recent advances in the renal mechanisms of fructose-induced salt-sensitive hypertension, including (pro)renin receptor-dependent activation of intrarenal renin-angiotensin system, increased nephron Na transport activity via sodium/hydrogen exchanger 3 and Na/K/2Cl cotransporter, increased renal uric acid production, decreased renal nitric oxide production, and increased renal reactive oxygen species production, and suggest actions based on these mechanisms that have therapeutic implications.
Blood Pressure ; Fructose ; adverse effects ; Humans ; Hypertension ; chemically induced ; physiopathology ; Kidney ; physiopathology ; Nitric Oxide ; metabolism ; Reactive Oxygen Species ; metabolism ; Renin-Angiotensin System ; Sodium Chloride, Dietary ; adverse effects ; Sodium-Hydrogen Exchanger 3 ; metabolism ; Uric Acid ; metabolism

This study aimed to investigate the antihypertensive effect and possible mechanism of Dendrobium officinale flos on hypertensive rats induced by high glucose and high fat compound alcohol. The hypertensive models were successfully made by high-glucose and high-fat diet, with gradient drinking for 4 weeks, and then divided into model control group, valsartan (5.7 mg·kg⁻¹) positive control group and D. officinale flos groups (3，1 g·kg⁻¹). After 6 weeks of treatment, the blood pressure of rats was measured regularly. After the last administration, endothelin-1 (ET-1), thromboxane B₂ (TXB₂), prostacyclin (PGI₂) and nitric oxide (NO) were tested. Endothelial nitric oxide synthase (eNOS) expression and lesion status in thoracic aorta were detected. The vascular endothelium dependent dilation of the thoracic aorta was detected by the isolated vascular loop tension test. The results showed that D. officinale flos could significantly reduce systolic blood pressure and mean arterial pressure in hypertensive rats, inhibit the thickening of thoracic aorta and the loss of endothelial cells, reduce plasma content of ET-1 and TXB₂, and increase the content of PGI₂ and NO. After long-term administration, vascular endothelium dependent dilation of the thoracic aorta was significantly increased, and could be blocked by the eNOS inhibitor (L-NAME) and increase the expression of eNOS. Therefore, D. officinale flos has an obvious antihypertensive effect on high glucose and high fat compound alcohol-induced hypertensive rats. Its mechanism may be correlated with the improvement of vascular diastolic function by protecting vascular endothelial cells, and finally resist hypertension.
Animals ; Antihypertensive Agents ; pharmacology ; Blood Pressure ; Dendrobium ; chemistry ; Diet, High-Fat ; Drugs, Chinese Herbal ; pharmacology ; Endothelin-1 ; blood ; Endothelium, Vascular ; drug effects ; Epoprostenol ; blood ; Glucose ; Hypertension ; chemically induced ; drug therapy ; Nitric Oxide ; blood ; Nitric Oxide Synthase Type III ; metabolism ; Rats ; T-Box Domain Proteins ; blood ; Vasodilation

Objective: To investigate the correlation of intermittent androgen-deprivation therapy (IADT) and continuous androgen-deprivation therapy (CADT) for advanced prostate cancer (PCa) with the risks of secondary diabetes mellitus (DM) and impaired glucose tolerance (IGT). METHODS: We conducted a retrospective case-control study of the advanced PCa patients treated by IADT or CADT in our hospital from January 2013 to December 2015. Based on the levels fasting blood glucose and 2-hour postprandial blood glucose, results of oral glucose tolerance test, and clinical symptoms of the patients, we statistically analyzed the IADT- or CADT-related risk factors for DM and IGT and the relationship of the body mass index (BMI), hypertension, smoking, and alcohol consumption with secondary DM and IGT. RESULTS: IADT was given to 53 (46.5%) of the patients, aged (69.1 ± 4.3) years, and CADT to 61 (53.5%), aged (70.2 ± 5.7) years. No statistically significant differences were observed in clinical characteristics between the two groups of patients (P > 0.05). BMI, blood pressure, smoking and drinking exhibited no significant influence on the development of DM or IGT either in the IADT (P > 0.05) or the CADT group. The incidence of IGT was significantly lower in the IADT than in the CADT group (P = 0.03), but that of DM showed no statistically significant difference between the two groups (P = 0.64). CONCLUSIONS Compared with CADT, IADT has a lower risk of IGT and a higher safety in the treatment of advanced prostate cancer.
Aged ; Alcohol Drinking ; adverse effects ; Androgen Antagonists ; adverse effects ; therapeutic use ; Blood Glucose ; metabolism ; Body Mass Index ; Case-Control Studies ; Diabetes Mellitus ; chemically induced ; Glucose Intolerance ; chemically induced ; Glucose Tolerance Test ; Humans ; Hypertension ; complications ; Male ; Prostatic Neoplasms ; drug therapy ; pathology ; Retrospective Studies ; Risk Factors ; Smoking ; adverse effects

BACKGROUNDClarifying the mechanisms underlying vascular smooth muscle cell (VSMC) proliferation is important for the prevention and treatment of vascular remodeling and the reverse of hyperplastic lesions. Previous research has shown that the gaseous signaling molecule sulfur dioxide (SO2) inhibits VSMC proliferation, but the mechanism for the inhibition of the angiotensin II (AngII)-induced VSMC proliferation by SO2has not been fully elucidated. This study was designed to investigate if SO2inhibited VSMC proliferation in mice with hypertension induced by AngII.

METHODSThirty-six male C57 mice were randomly divided into control, AngII, and AngII + SO2groups. Mice in AngII group and AngII + SO2group received a capsule-type AngII pump implanted under the skin of the back at a slow-release dose of 1000 ng·kg-1·min-1. In addition, mice in AngII + SO2received intraperitoneal injections of SO2donor. Arterial blood pressure of tail artery was determined. The thickness of the aorta was measured by elastic fiber staining, and proliferating cell nuclear antigen (PCNA) and phosphorylated-extracellular signal-regulated kinase (P-ERK) were detected in aortic tissues. The concentration of SO2 in serum and aortic tissue homogenate supernatant was measured using high-performance liquid chromatography with fluorescence determination. In the in vitro study, VSMC of A7R5 cell lines was divided into six groups: control, AngII, AngII + SO2, PD98059 (an inhibitor of ERK phosphorylation), AngII + PD98059, and AngII + SO2 + PD98059. Expression of PCNA, ERK, and P-ERK was determined by Western blotting.

RESULTSIn animal experiment, compared with the control group, AngII markedly increased blood pressure (P < 0.01) and thickened the aortic wall in mice (P < 0.05) with an increase in the expression of PCNA (P < 0.05). SO2, however, reduced the systemic hypertension and the wall thickness induced by AngII (P < 0.05). It inhibited the increased expression of PCNA and P-ERK induced by AngII (P < 0.05). In cell experiment, PD98059, an ERK phosphorylation inhibitor, blocked the inhibitory effect of SO2on VSMC proliferation (P < 0.05).

CONCLUSIONSERK signaling is involved in the mechanisms by which SO2inhibits VSMC proliferation in AngII-induced hypertensive mice via ERK signaling.

Angiotensin II ; pharmacology ; Animals ; Cell Proliferation ; drug effects ; Extracellular Signal-Regulated MAP Kinases ; metabolism ; Hypertension ; chemically induced ; drug therapy ; Male ; Mice ; Muscle, Smooth, Vascular ; cytology ; drug effects ; Signal Transduction ; drug effects ; Sulfur Dioxide ; therapeutic use

Alkaloids from Ba lotus seeds (ABLS) are a kind of important functional compounds in lotus seeds. The present study was designed to determine its hypertension prophylactic effects in the L-NNA-induced mouse hypertension model. The mice were treated with ABLS, the serum and tissues levels of NO, MDA, ET-1, VEGF, and CGRP were determined using the experimental kits, the mRNA levels of various genes in the heart muscle and blood vessel tissues were further determined by RT-PCR assay. ABLS could reduce the systolic blood pressure (SBP), mean blood pressure (MBP), and diastolic blood pressure (DBP), compared to that of the model control group. After ABLS treatment, the NO (nitric oxide) contents in serum, heart, liver, kidney and stomach of the mice were higher than that of the control mice, but the MDA (malonaldehyde) contents were lower than that of the control mice. The serum levels of ET-1 (endothelin-1), VEGF (vascular endothelial growth factor) were decreased after ABLS treatment, but CGRP (calcium gene related peptide) level was increased. The ABLS treated mice had higher mRNA expressions of HO-1, nNOS, and eNOS and lower expressions of ADM, RAMP2, IL-1β, TNF-α, and iNOS than the control mice. Higher concentration of ABLS had greater prophylactic effects, which were close to that of the hypertension drug captopril. These results indicated the hypertension prophylactic effects of ABLS could be further explored as novel medicine or functional food in the future.
Alkaloids ; administration & dosage ; Animals ; Blood Pressure ; drug effects ; Disease Models, Animal ; Humans ; Hypertension ; chemically induced ; drug therapy ; metabolism ; physiopathology ; Interleukin-1beta ; genetics ; metabolism ; Male ; Mice ; Mice, Inbred ICR ; Nitroarginine ; Nymphaeaceae ; chemistry ; Seeds ; chemistry ; Tumor Necrosis Factor-alpha ; genetics ; metabolism ; Vascular Endothelial Growth Factor A ; genetics ; metabolism

Pulmonary arterial hypertension (PAH) causes right ventricular failure due to a gradual increase in pulmonary vascular resistance. The purposes of this study were to confirm the engraftment of human umbilical cord blood-mesenchymal stem cells (hUCB-MSCs) placed in the correct place in the lung and research on changes of hemodynamics, pulmonary pathology, immunomodulation and several gene expressions in monocrotaline (MCT)-induced PAH rat models after hUCB-MSCs transfusion. The rats were grouped as follows: the control (C) group; the M group (MCT 60 mg/kg); the U group (hUCB-MSCs transfusion). They received transfusions via the external jugular vein a week after MCT injection. The mean right ventricular pressure (RVP) was significantly reduced in the U group after the 2 week. The indicators of RV hypertrophy were significantly reduced in the U group at week 4. Reduced medial wall thickness in the pulmonary arteriole was noted in the U group at week 4. Reduced number of intra-acinar muscular pulmonary arteries was observed in the U group after 2 week. Protein expressions such as endothelin (ET)-1, endothelin receptor A (ERA), endothelial nitric oxide synthase (eNOS) and matrix metalloproteinase (MMP)-2 significantly decreased at week 4. The decreased levels of ERA, eNOS and MMP-2 immunoreactivity were noted by immnohistochemical staining. After hUCB-MSCs were administered, there were the improvement of RVH and mean RVP. Reductions in several protein expressions and immunomodulation were also detected. It is suggested that hUCB-MSCs may be a promising therapeutic option for PAH.
Animals ; Cytokines/metabolism ; Disease Models, Animal ; Endothelin-1/metabolism ; Fetal Blood/*cytology ; Gene Expression Regulation/drug effects ; Hemodynamics ; Humans ; Hypertension, Pulmonary/chemically induced/*therapy ; Hypertrophy, Right Ventricular/physiopathology ; Immunohistochemistry ; Lung/metabolism/pathology ; Male ; Matrix Metalloproteinase 2/metabolism ; *Mesenchymal Stem Cell Transplantation ; Mesenchymal Stromal Cells/*cytology/metabolism ; Monocrotaline/toxicity ; Nitric Oxide Synthase Type III/metabolism ; Pulmonary Artery/pathology ; Rats ; Rats, Sprague-Dawley ; Receptor, Endothelin A/metabolism

The aim of the present study is to investigate the protective effect of chrysin (5,7-dihydroxyflavone) on right ventricular remodeling in a rat model of monocrotaline-induced pulmonary arterial hypertension (PAH). PAH rats were induced by a single injection of monocrotaline (60 mg x kg(-1), sc) and were administered with chrysin (50 or 100 mg x kg(-1) x d(-1)) for 4 weeks. At the end of experiment, the right ventricular systolic pressure (RVSP) and mean pulmonary artery pressure (mPAP) were monitored via the right jugular vein catheterization into the right ventricle. Right ventricle (RV) to left ventricle (LV) + septum (S) and RV to tibial length were calculated. Right ventricular morphological change was observed by HE staining. Masson's trichrome stain was used to demonstrate collagen deposition. The total antioxidative capacity (T-AOC) and malondialdehyde (MDA) levels in right ventricle were determined according to the manufacturer's instructions. The expressions of collagen I, collagen III, NADPH oxidase 4 (NOX4) and nuclear factor-kappa B (NF-κB) were analyzed by immunohistochemisty, qPCR and (or) Western blot. The results showed that chrysin treatment for 4 weeks attenuated RVSP, mPAP and right ventricular remodeling index (RV/LV+S and RV/Tibial length) of PAH rats induced by monocrotaline. Furthermore, monocrotaline-induced right ventricular collagen accumulation and collagen I and collagen III expression were both significantly suppressed by chrysin. The expressions of NOX4, NF-κB and MDA contents were obviously decreased, while the T-AOC was significantly increased in right ventricule from PAH rats with chrysin treatment. These results suggest that chrysin ameliorates right ventricular remodeling of PAH induced by monocrotaline in rats through its down-regulating of NOX4 expression and antioxidant activity, and inhibiting NF-κB expression and collagen accumulation.
Animals ; Blotting, Western ; Collagen ; metabolism ; Disease Models, Animal ; Flavonoids ; pharmacology ; Heart Ventricles ; drug effects ; metabolism ; Hypertension, Pulmonary ; chemically induced ; metabolism ; Monocrotaline ; toxicity ; NADPH Oxidase 4 ; NADPH Oxidases ; metabolism ; NF-kappa B ; metabolism ; Rats ; Ventricular Remodeling ; drug effects