scholarly journals Chronic administration of apocynin and catalase ameliorates the blood pressure and renal functional parameters attributed by L-NAME induced systemic arterial hypertension in Wistar-Kyoto rats: The role of oxidative stress

2018 ◽  
Vol 9 ◽  
Author(s):  
Yong Chia Tan ◽  
Munavvar Abdul Sattar ◽  
Nurzalina Abdul Karim Khan ◽  
Vikneswaran Murugaiyah ◽  
Ashfaq Ahmed ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Arterial Hypertension ◽  
Chronic Administration ◽  
Functional Parameters ◽  
Systemic Arterial Hypertension ◽  
Wistar Kyoto Rats ◽  
Wistar Kyoto

Increased Pressor Responsiveness to Enkephalin in Spontaneously Hypertensive Rats: The Role of Vasopressin

1980 ◽  
Vol 59 (s6) ◽  
pp. 235s-237s ◽  
Author(s):  
R. W. Rockhold ◽  
J. T. Crofton ◽  
L. Share
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Pressor Response ◽  
Cardiovascular Effects ◽  
Hypertensive Rats ◽  
Methionine Enkephalin ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto Rats ◽  
Wistar Kyoto

1. The cardiovascular effects of an enkephalin analogue were examined in spontaneously hypertensive and normotensive Wistar-Kyoto rats. (D-Ala2)-methionine enkephalin caused a biphasic increase in blood pressure and an increase in heart rate after intracerebroventricular injection. 2. The initial pressor response to (D-Ala2)-methionine enkephalin was greater in hypertensive than in normotensive rats. No difference was noted between groups during the secondary pressor response. Heart rate increases paralleled the secondary increase in blood pressure. 3. Naloxone pretreatment abolished the secondary increase in blood pressure and the tachycardia, but did not blunt the initial pressor response in female Wistar-Kyoto rats. 4. Plasma levels of arginine vasopressin were depressed during the plateau phase of the pressor response in hypertensive rats given intracerebroventricular (d-Ala2)-methionine enkephalin. 5. The results suggest that the cardiovascular effects of central enkephalin are not due to vasopressin, but may involve activation of the sympathetic nervous system.

Contribution of Vascular Nitric Oxide to Basal Blood Pressure in Conscious Spontaneously Hypertensive Rats and Normotensive Wistar Kyoto Rats

1995 ◽  
Vol 89 (2) ◽  
pp. 177-182 ◽  
Author(s):  
Naoyoshi Minami ◽  
Yutaka Imai ◽  
Jun-Ichiro Hashimoto ◽  
Keishi Abe
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Mean Arterial Pressure ◽  
Methyl Ester ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Wistar Kyoto Rats ◽  
Basal Blood Pressure ◽  
Wistar Kyoto

1. The aim of this study was to clarify the extent to which vascular nitric oxide contributes to basal blood pressure in conscious spontaneously hypertensive rats and normotensive Wistar Kyoto rats. 2. The contribution of vascular nitric oxide to maintenance of blood pressure was estimated by measuring the pressor response to an intravenous injection of nitric oxide synthase inhibitor, Nω-l-arginine methyl ester, given after serial injections of captopril, vasopressin V1-receptor antagonist (V1-antagonist) and ganglion blocker (pentolinium) in conscious spontaneously hypertensive and Wistar Kyoto rats aged 20–28 weeks. To estimate the ‘amplifier property’ of hypertrophied vasculature in spontaneously hypertensive rats, which is known to modulate pressor responses, the lower blood pressure plateau after serial injections of captopril, V1-antagonist and pentolinium and the maximum blood pressure elicited by subsequent injection of increasing doses of phenylephrine were also measured. 3. The serial injections of captopril, V1-antagonist and pentolinium decreased mean arterial pressure from 164 ± 9 mmHg to 67 ± 2 mmHg and from 117 ± 2 mmHg to 49 ± 1 mmHg in spontaneously hypertensive and Wistar Kyoto rats respectively. The subsequent injection of Nω-l-arginine methyl ester restored mean arterial pressure almost to its control levels in both spontaneously hypertensive and Wistar Kyoto rats. The absolute changes in mean arterial pressure elicited by Nω-l-arginine methyl ester were significantly greater in spontaneously hypertensive than in Wistar Kyoto rats (P < 0.01), but there was no significant difference in the responses to Nω-l-arginine methyl ester when they were expressed as percentages of either the lower blood pressure plateau or maximum blood pressure. 4. These results indicate that basal blood pressure in both spontaneous hypertensive and Wistar Kyoto rats is maintained by a balance between vascular nitric oxide and major pressor systems. They also suggest that the vasodilatory effect of vascular nitric oxide does not differ between spontaneously hypertensive and Wistar Kyoto rats, and that the increased pressor effect of Nω-l-arginine methyl ester in spontaneously hypertensive rats is due to a vascular amplifier mechanism.

Cardiac baroreflex dysfunction in patients with pulmonary arterial hypertension at rest and during orthostatic stress: Role of the peripheral chemoreflex

2021 ◽  
Author(s):  
Marcelle Paula-Ribeiro ◽  
Indyanara C. Ribeiro ◽  
Liliane C. Aranda ◽  
Talita M. Silva ◽  
Camila M. Costa ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Early Stage ◽  
Pressure Fluctuations ◽  
Sit To Stand ◽  
Peak Aerobic Capacity ◽  
Pulmonary Arterial ◽  
Peripheral Chemoreflex

The baroreflex integrity in early-stage pulmonary arterial hypertension (PAH) remains uninvestigated. A potential baroreflex impairment could be functionally relevant and possibly mediated by enhanced peripheral chemoreflex activity. Thus, we investigated 1) the cardiac baroreflex in non-hypoxemic PAH; 2) the association between baroreflex indexes and peak aerobic capacity (i.e., V̇O2peak); and 3) the peripheral chemoreflex contribution to the cardiac baroreflex. Nineteen patients and 13 age- and sex-matched healthy adults (HA) randomly inhaled either 100% O2 (peripheral chemoreceptors inhibition) or 21% O2 (control session), while at rest and during a repeated sit-to-stand maneuver. Beat-by-beat analysis of R-R intervals and systolic blood pressure provided indexes of cardiac baroreflex sensitivity (cBRS) and effectiveness (cBEI). The PAH group had lower cBEIALL at rest (mean ± SD: PAH = 0.5 ± 0.2 vs HA = 0.7 ± 0.1 a.u., P = 0.02) and lower cBRSALL (PAH = 6.8 ± 7.0 vs HA = 9.7 ± 5.0 ms mmHg-1, P < 0.01) and cBEIALL (PAH = 0.4 ± 0.2 vs HA= 0.6 ± 0.1 a.u., P < 0.01) during the sit-to-stand maneuver versus the HA group. The cBEI during the sit-to-stand maneuver was independently correlated to V̇O2peak (partial r = 0.45, P < 0.01). Hyperoxia increased cBRS and cBEI similarly in both groups at rest and during the sit-to-stand maneuver. Therefore, cardiac baroreflex dysfunction was observed under spontaneous and, most notably, provoked blood pressure fluctuations in non-hypoxemic PAH, was not influenced by the peripheral chemoreflex, and was associated with lower V̇O2peak suggesting it could be functionally relevant.

MO092THE ROLE OF CALCIUM IN UROMODULIN EXPRESSION AND SECRETION FROM RENAL MEDULLARY EPITHELIAL CELLS OF HYPERTENSIVE AND NORMOTENSIVE RATS

2021 ◽  
Vol 36 (Supplement_1) ◽  
Author(s):  
Philipp Boder ◽  
Sheon Mary ◽  
Lesley Graham ◽  
Christian Delles
Keyword(s):  
Blood Pressure ◽  
Epithelial Cells ◽  
Mrna Level ◽  
Extracellular Calcium ◽  
Female Rats ◽  
Thick Ascending Limb ◽  
Molecular Signaling ◽  
Extracellular Secretion ◽  
Wistar Kyoto

Abstract Background and Aims Uromodulin (UMOD) is the most abundantly secreted protein found within the urine, primarily produced by medullary thick ascending limb (mTAL) epithelial cells of the kidneys. There is accruing genetic evidence implicating UMOD in blood pressure regulation and consequently hypertension. The molecular signaling induced by calcium in the kidney and its influence on blood pressure are not well understood. The aim of this study was to investigate the potential role of extracellular calcium and the calcium-sensing receptor (CaSR) in mTAL on UMOD production and secretion in TAL cells with the hope of defining novel clinical targets for the treatment of hypertension. Method Kidneys were harvested from normotensive Wistar-Kyoto (WKY) and stroke-prone spontaneously hypertensive (SHRSP) female rats. To determine the effect of extracellular calcium on UMOD secretion, mTAL tubules were incubated in media with and without 1mM calcium, nifedipine (10µM), NPS2143 (1 or 5 µM) and spermine (2mM). Extracellular and intracellular UMOD protein levels were detected by Western blot. Gene expression of Umod was determined by qRT-PCR. Results Calcium increased mTAL tubule UMOD secretion in WKY and SHRSP. Nifedipine slightly decreased UMOD secretion in WKY without calcium. In both strains, NPS2143 increased calcium-induced UMOD secretion, with an enhanced effect in SHRSP. Stimulation of CaSR with spermine decreased UMOD secretion in WKY. Analysis of intracellular UMOD levels in these conditions demonstrated increased accumulation when extracellular secretion was low, and vice versa. Incubation of primary mTAL cells with calcium confirmed increased localisation of UMOD at the membrane compared to the cytosol, without any major differences in cell morphology. The Umod mRNA level changes were not statistically significant among conditions. Conclusion Trafficking of UMOD in the mTAL is influenced by the type of CaSR ligand and the biased nature of G-protein coupled CaSR signalling. Unravelling the signalling events post-calcium will be necessary for identification of key regulators of UMOD secretion and provide new sites for therapeutic intervention in hypertension.

scholarly journals The Key Role of Ambulatory Blood Pressure Monitoring in the Detection of Masked Hypertension and Other Phenomena in Frail Geriatric Patients

Medicina ◽  
2021 ◽  
Vol 57 (11) ◽  
pp. 1221
Author(s):  
Marek Koudelka ◽  
Eliška Sovová
Keyword(s):  
Blood Pressure ◽  
Arterial Hypertension ◽  
Ambulatory Blood Pressure Monitoring ◽  
Ambulatory Blood Pressure ◽  
Geriatric Patients ◽  
Blood Pressure Monitoring ◽  
Target Range ◽  
Masked Hypertension ◽  
Pressure Monitoring

Background and Objectives: This study aims to determine prevalence of masked uncontrolled hypertension (MUH) in frail geriatric patients with arterial hypertension and thus show the role of ambulatory blood pressure monitoring (ABPM) since hypertension occurs in more than 80% of people 60+ years and cardiovascular diseases are the main cause of death worldwide. Despite modern pharmacotherapy, use of combination therapy and normal office blood pressure (BP), patients’ prognoses might worsen due to inadequate therapy (never-detected MUH). Materials and Methods: 118 frail geriatric patients (84.2 ± 4.4 years) treated for arterial hypertension with office BP < 140/90 mmHg participated in the study. 24-h ABPM and clinical examination were performed. Results: Although patients were normotensive in the office, 24-h measurements showed that BP values in 72% of hypertensives were not in the target range: MUH was identified in 47 (40%) patients during 24 h, in 48 (41%) patients during daytime and nocturnal hypertension in 60 (51%) patients. Conclusions: ABPM is essential for frail geriatric patients due to high prevalence of MUH, which cannot be detected based on office BP measurements. ABPM also helps to detect exaggerated morning surge, isolated systolic hypertension, dipping/non-dipping, and set and properly manage adequate treatment, which reduces incidence of cardiovascular events and contributes to decreasing the financial burden of society.

scholarly journals Dificuldades no Acompanhamento de Portadores de Hipertensão Arterial Sistêmica Utilizando a Ferramenta de Monitoramento Residencial da Pressão Arterial / Difficulties in Monitoring Patients with Systemic Arterial Hypertension Using the Home Blood Pressure Monitoring Tool

2021 ◽  
Vol 15 (54) ◽  
pp. 448-456
Author(s):  
Josicleiton Morais de Lima ◽  
Amanda Camboim De Sá Santos ◽  
João Paulo Soares Rafael ◽  
Victor Lucas Avelino Galindo ◽  
Milena Nunes Alves de Sousa
Keyword(s):  
Blood Pressure ◽  
Arterial Hypertension ◽  
Blood Pressure Monitoring ◽  
Home Blood Pressure ◽  
Home Blood Pressure Monitoring ◽  
Monitoring Tool ◽  
Pressure Monitoring ◽  
Electronic Library ◽  
Systemic Arterial Hypertension

  Resumo: O objetivo deste trabalho foi identificar as principais dificuldades encontradas no acompanhamento dos portadores de Hipertensão Arterial Sistêmica (HAS) utilizando a ferramenta MRPA, bem como as vantagens e eficácia do tratamento ao hipertenso. Foi realizado o levantamento dos artigos científicos nas bases de dados eletrônicas Google Acadêmico e Scientific Electronic Library Online. Após a inserção dos critérios de inclusão e exclusão foram selecionados dez estudos publicados entre 2005 e 2020 para compor a amostra. As dificuldades apontadas na literatura foram: o declínio do uso da ferramenta em longo prazo, dificuldade no manuseio do aparelho, número insuficiente de medidas pelos pacientes dos estudos e indução de estresse e ansiedade nos pacientes. Além disso, foram averiguadas vantagens do uso da ferramenta e a eficácia desse tipo de monitorização no tratamento ao portador de HAS. A ferramenta MRPA é eficaz no diagnóstico e acompanhamento de hipertensos, e para melhor usufruir dessa estratégia, é preciso que os profissionais estejam atentos às dificuldades apontadas e solucioná-las.   

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