scholarly journals The effects of pertussis toxin-treatment on integrated vasoactive response of vascular system in spontaneously hypertensive rats

2008 ◽  
pp. 137-139
Author(s):  
S Čačányiová ◽  
F Kristek ◽  
J Kuneš ◽  
J Zicha
Keyword(s):  
Pertussis Toxin ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Vascular System ◽  
Pressor Response ◽  
Experimental Hypertension ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
The Right ◽  
Hypotensive Response

We investigated the effect of pertussis toxin (PTX) on hypotensive response induced by acetylcholine (ACh) and bradykinin (BK) and on noradrenaline (NA)-induced pressor response in spontaneously hypertensive rats (SHR). Fifteenweek-old Wistar rats and age-matched SHR were used. Half of SHR received PTX (10 µg/kg/i.v.) and the experiments were performed 48 h later. After the anesthesia the right carotid artery was cannulated in order to record blood pressure (BP). The hypotensive response to ACh was enhanced in SHR compared to Wistar rats. After pretreatment of SHR with PTX the hypotensive response to ACh was reduced compared to untreated SHR and it was also diminished in comparison to Wistar rats. Similarly, the hypotensive response to BK was also decreased after PTX pretreatment. The pressor response to NA was increased in SHR compared to Wistar rats. NA-induced pressor response was considerably decreased after PTX pretreatment compared to untreated SHR. In conclusion, the enhancement of hypotensive and pressor responses in SHR was abolished after PTX pretreatment. Our results suggested that the activation of PTXsensitive inhibitory Gi proteins is involved in the regulation of integrated vasoactive responses in SHR and PTX pretreatment could be effectively used for modification of BP regulation in this type of experimental hypertension.

scholarly journals Inactivation of Gi proteins by pertussis toxin diminishes the effectiveness of adrenergic stimuli in conduit arteries from spontaneously hypertensive rats

2008 ◽  
pp. 299-302
Author(s):  
A Zemančíková ◽  
J Török ◽  
J Zicha ◽  
J Kuneš
Keyword(s):  
Pulmonary Artery ◽  
Thoracic Aorta ◽  
Pertussis Toxin ◽  
Mesenteric Artery ◽  
Spontaneously Hypertensive Rats ◽  
Main Pulmonary Artery ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
The Right ◽  
Gi Proteins

Treatment with pertussis toxin (PTX) which eliminates the activity of Gi proteins effectively reduces blood pressure (BP) and vascular resistance in spontaneously hypertensive rats (SHR). In this study we have compared the functional characteristics of isolated arteries from SHR with and without PTX-treatment (10 μg/kg i.v., 48 h before the experiment). Rings of thoracic aorta, superior mesenteric artery and main pulmonary artery were studied under isometric conditions to measure the reactivity of these vessels to receptor agonists and to transmural electrical stimuli. We have found that the treatment of SHR with PTX had no effect on endothelium-dependent relaxation of thoracic aorta induced by acetylcholine. In PTX-treated SHR, the maximum contraction of mesenteric artery to exogenous noradrenaline was reduced and the dose-response curve to cumulative concentration of noradrenaline was shifted to the right. Similarly, a reduction in the magnitude of neurogenic contractions elicited by electrical stimulation of perivascular nerves was observed in the mesenteric artery from PTX-treated SHR. PTX treatment of SHR also abolished the potentiating effect of angiotensin II on neurogenic contractions of the main pulmonary artery. These results indicate that PTX treatment markedly diminishes the effectiveness of adrenergic stimuli in vasculature of SHR. This could importantly affect BP regulation in genetic hypertension.

scholarly journals Hyperbaric Oxygen Preconditioning Upregulates Heme OxyGenase-1 and Anti-Apoptotic Bcl-2 Protein Expression in Spontaneously Hypertensive Rats with Induced Postischemic Acute Kidney Injury

2021 ◽  
Vol 22 (3) ◽  
pp. 1382
Author(s):  
Jelena Nesovic Ostojic ◽  
Milan Ivanov ◽  
Nevena Mihailovic-Stanojevic ◽  
Danijela Karanovic ◽  
Sanjin Kovacevic ◽  
...  
Keyword(s):  
Acute Kidney Injury ◽  
Protein Expression ◽  
Hyperbaric Oxygen ◽  
Heme Oxygenase ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Kidney Injury ◽  
Heme Oxygenase 1 ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

Renal ischemia and reperfusion (I/R) injury is the most common cause of acute kidney injury (AKI). Pathogenesis of postischemic AKI involves hemodynamic changes, oxidative stress, inflammation process, calcium ion overloading, apoptosis and necrosis. Up to date, therapeutic approaches to treat AKI are extremely limited. Thus, the aim of this study was to evaluate the effects of hyperbaric oxygen (HBO) preconditioning on citoprotective enzyme, heme oxygenase-1 (HO-1), pro-apoptotic Bax and anti-apoptotic Bcl-2 proteins expression, in postischemic AKI induced in normotensive Wistar and spontaneously hypertensive rats (SHR). The animals were randomly divided into six experimental groups: SHAM-operated Wistar rats (W-SHAM), Wistar rats with induced postischemic AKI (W-AKI) and Wistar group with HBO preconditioning before AKI induction (W-AKI + HBO). On the other hand, SHR rats were also divided into same three groups: SHR-SHAM, SHR-AKI and SHR-AKI + HBO. We demonstrated that HBO preconditioning upregulated HO-1 and anti-apoptotic Bcl-2 protein expression, in both Wistar and SH rats. In addition, HBO preconditioning improved glomerular filtration rate, supporting by significant increase in creatinine, urea and phosphate clearances in both rat strains. Considering our results, we can also say that even in hypertensive conditions, we can expect protective effects of HBO preconditioning in experimental model of AKI.

scholarly journals Identification of Aortic Proteins Involved in Arterial Stiffness in Spontaneously Hypertensive Rats Treated With Perindopril:A Proteomic Approach

2021 ◽  
Vol 12 ◽  
Author(s):  
Danyelle S. Miotto ◽  
Aline Dionizio ◽  
André M. Jacomini ◽  
Anderson S. Zago ◽  
Marília Afonso Rabelo Buzalaf ◽  
...  
Keyword(s):  
Arterial Stiffness ◽  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Molecular Mechanisms ◽  
Rho Kinase ◽  
Vascular Wall ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Cytoskeleton Organization ◽  
Proteomic Approach

Arterial stiffness, frequently associated with hypertension, is associated with disorganization of the vascular wall and has been recognized as an independent predictor of all-cause mortality. The identification of the molecular mechanisms involved in aortic stiffness would be an emerging target for hypertension therapeutic intervention. This study evaluated the effects of perindopril on pulse wave velocity (PWV) and on the differentially expressed proteins in aorta of spontaneously hypertensive rats (SHR), using a proteomic approach. SHR and Wistar rats were treated with perindopril (SHRP) or water (SHRc and Wistar rats) for 8 weeks. At the end, SHRC presented higher systolic blood pressure (SBP, +70%) and PWV (+31%) compared with Wistar rats. SHRP had higher values of nitrite concentration and lower PWV compared with SHRC. From 21 upregulated proteins in the aortic wall from SHRC, most of them were involved with the actin cytoskeleton organization, like Tropomyosin and Cofilin-1. After perindopril treatment, there was an upregulation of the GDP dissociation inhibitors (GDIs), which normally inhibits the RhoA/Rho-kinase/cofilin-1 pathway and may contribute to decreased arterial stiffening. In conclusion, the results of the present study revealed that treatment with perindopril reduced SBP and PWV in SHR. In addition, the proteomic analysis in aorta suggested, for the first time, that the RhoA/Rho-kinase/Cofilin-1 pathway may be inhibited by perindopril-induced upregulation of GDIs or increases in NO bioavailability in SHR. Therefore, we may propose that activation of GDIs or inhibition of RhoA/Rho-kinase pathway could be a possible strategy to treat arterial stiffness.

Abstract P150: Sex Difference of Hypertension in Spontaneously Hypertensive Rats: Role of Mitochondrial Oxidative Stress

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Rodrigo O Maranon ◽  
Carolina Dalmasso ◽  
Chetal N Patil ◽  
Jane F Reckelhoff
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Sex Difference ◽  
Spontaneously Hypertensive Rats ◽  
Pressor Response ◽  
Premenopausal Women ◽  
Hypertensive Rats ◽  
Mitochondrial Oxidative Stress ◽  
Spontaneously Hypertensive ◽  
Mitochondrial Superoxide

Men have higher blood pressure (BP) than premenopausal women. Pressor response to oxidative stress may be a major contributor to the sex difference in BP control. Mitochondrial oxidative stress is associated with hypertension; however, whether mitochondrial oxidative stress plays a role in the sex difference in BP is unknown. In the present study, we tested the hypothesis that mitochondrial oxidative stress contributes to the sex difference in BP regulation in spontaneously hypertensive rats (SHR). Young intact (iYMSHR) and castrated males (cYMSHR), and females SHR (YFSHR) (3 mos of age) were implanted with radiotelemeters, and after a 4 day baseline BP, were treated with mitoTempo (0.75 mg/kg/d, sc minipumps), a specific scavenger of mitochondrial superoxide, for 7 days. Following 10 days washout of mito-tempo, rats were treated with Tempol (30 mg/kg/day, po drinking water) for 7 days. iYMSHR have higher blood pressure (by telemetry) than cYMSHR and YFSHR (148±1 mmHg, n=5, vs 132±1 mmHg, n=5, and 139±1 mmHg, n=5; p<0.01, respectively). MitoTempo reduced BP by 6% in iYMSHR (147±1 vs 139±1, n=5; p<0.05) compared to females (3%: 139±1 vs 136±1; n=5; p: NS) and castrated males (4.5%: 132±1 vs 126±1, n=5; p<0.05). After 10 days washout, tempol reduced BP only in iYMSHR (144±1 vs 130±1 mmHg, n=5; p<0.05). Our results suggest that mitochondrial oxidative stress may contribute to BP regulation in male SHR, but has no effect in females. The data also suggest that the presence of testosterone is necessary for the pressor response to oxidative stress in males since Tempol had no effect on BP in castrated males. Further studies examining the effect of steroid hormones and mitochondria in BP regulation are necessary to elucidate the importance of mitochondrial oxidative stress on sex difference of hypertension.

Vasopressin V2 receptor enhances gain of baroreflex in conscious spontaneously hypertensive rats

1999 ◽  
Vol 276 (3) ◽  
pp. R872-R879 ◽  
Author(s):  
Donella B. Sampey ◽  
Louise M. Burrell ◽  
Robert E. Widdop
Keyword(s):  
Receptor Antagonist ◽  
Spontaneously Hypertensive Rats ◽  
Pressor Response ◽  
Receptor Subtype ◽  
Hypertensive Rats ◽  
Receptor Antagonists ◽  
Spontaneously Hypertensive ◽  
Wky Rats ◽  
Baroreflex Function ◽  
Shr And Wky Rats

The aim of the present study was to determine the receptor subtype involved in arginine vasopressin (AVP)-induced modulation of baroreflex function in spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats using novel nonpeptide AVP V1- and V2-receptor antagonists. Baroreceptor heart rate (HR) reflex was investigated in both SHR and WKY rats which were intravenously administered the selective V1- and V2-receptor antagonists OPC-21268 and OPC-31260, respectively. Baroreflex function was assessed by obtaining alternate pressor and depressor responses to phenylephrine and sodium nitroprusside, respectively, to construct baroreflex curves. In both SHR and WKY rats baroreflex activity was tested before and after intravenous administration of vehicle (20% DMSO), OPC-21268 (10 mg/kg), and OPC-31260 (1 and 10 mg/kg). Vehicle did not significantly alter basal mean arterial pressure (MAP) and HR values or baroreflex function in SHR or WKY rats. The V1-receptor antagonist had no significant effect on resting MAP or HR values or on baroreflex parameters in both groups of rats, although this dose was shown to significantly inhibit the pressor response to AVP (5 ng iv; ANOVA, P < 0.05). In SHR but not WKY rats the V2-receptor antagonist significantly attenuated the gain (or slope) of the baroreflex curve (to 73 ± 3 and 79 ± 7% of control for 1 and 10 mg/kg, respectively), although AVP-induced pressor responses were also attenuated with the higher dose of the V2-receptor antagonist. These findings suggest that AVP tonically enhances baroreflex function through a V2 receptor in the SHR.

scholarly journals Age-related differences in pressor response to norepinephrine (NE) and tyramine (Ty) in spontaneously hypertensive rats (SHR)

1988 ◽  
Vol 46 ◽  
pp. 128
Author(s):  
Yoshiko Masubuchi ◽  
Toshio Kumai ◽  
Taiichiro Ohno ◽  
Masami Tanaka ◽  
Minoru Watanabe ◽  
...  
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Pressor Response ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Age Related

Intracellular Cation Activities and Concentrations in Spontaneously Hypertensive and Normotensive Rats

1981 ◽  
Vol 61 (s7) ◽  
pp. 41s-43s ◽  
Author(s):  
W. Zidek ◽  
H. Vetter ◽  
H. Zumkley ◽  
H. Losse
Keyword(s):  
Spontaneously Hypertensive Rats ◽  
Wistar Rats ◽  
Binding Capacity ◽  
Free Water ◽  
Electrolyte Composition ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Intracellular Na Activity ◽  
Intracellular Concentrations

1. The intracellular concentrations of Na+, K+ and Ca2+ were measured in the erythrocytes of spontaneously hypertensive rats and normotensive Wistar rats. 2. The intracellular Na+ concentration in hypertensive rats was slightly elevated at 3.16 ± 0.25 compared with 2.85 ± 0.35 mmol/l (P ≈ 0.05) and intracellular Na+ activity was markedly increased in hypertensive rats. 3. Intracellular Ca2+ activity was 7519 ± 28 990 nmol/l of free water in hypertensive rats compared with 123 ± 98 in controls (P &lt; 0.01). 4. The cytoplasm of hypertensive animals did not buffer Ca2+ as effectively as that of normal animals. 5. It is concluded that a decreased binding capacity of intracellular macromolecules for Na+ and Ca2+ may explain the disturbances of intracellular electrolyte composition in spontaneously hypertensive rats.

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