scholarly journals Vasorelaxant and Hypotensive Effects of Jaboticaba Fruit (Myrciaria cauliflora) Extract in Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Daniela Medeiros Lobo de Andrade ◽  
Carolina de Fátima Reis ◽  
Patrícia Ferreira da Silva Castro ◽  
Leonardo Luiz Borges ◽  
Nathalia Oda Amaral ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Femoral Vein ◽  
Soluble Guanylyl Cyclase ◽  
Aortic Blood Flow ◽  
Aortic Blood ◽  
Cox Inhibitor

This study’s aim was to determine the effect of hydroalcoholic extract ofM. cauliflora(HEMC) on vascular tension and blood pressure in rats. In ourin vitrostudies using precontracted isolated aortas from rats, HEMC and acetylcholine (positive control) induced relaxation only in vessels with endothelium. Pretreatment with L-NAME (NO synthase inhibitor) or ODQ (soluble guanylyl cyclase (sGC) inhibitor) abolished the HEMC-induced relaxation. The treatment with MDL-12,330A (adenylyl cyclase (AC) inhibitor) or diclofenac (COX inhibitor) reduced HEMC-induced vasorelaxation. The blockade of muscarinic andβ-adrenergic receptors (by atropine and propranolol, resp.) did not promote changes in HEMC-induced vasorelaxation. In ourin vivostudies, catheters were inserted into the right femoral vein and artery of anesthetized rats for HEMC infusion and the measurement of blood pressure, heart rate, and aortic blood flow. The intravenous infusion of HEMC produced hypotension and increased aortic blood flow with no changes in heart rate. These findings showed that HEMC induces endothelium-dependent vascular relaxation and hypotension with no alteration in heart rate. The NO/sGC/cGMP pathway seems to be the main cellular route involved in the vascular responsiveness.

S-nitroso-albumin carries a thiol-labile pool of nitric oxide, which causes venodilation in the rat

2005 ◽  
Vol 289 (2) ◽  
pp. H916-H923 ◽  
Author(s):  
Nelson N. Orie ◽  
Patrick Vallance ◽  
Dean P. Jones ◽  
Kevin P. Moore
Keyword(s):  
Nitric Oxide ◽  
Molecular Weight ◽  
Blood Flow ◽  
Vascular Function ◽  
Low Molecular Weight ◽  
Aortic Blood Flow ◽  
Hemodynamic Effects ◽  
Rapid Decomposition ◽  
Aortic Blood

It is now established that S-nitroso-albumin (SNO-albumin) circulates at low nanomolar concentrations under physiological conditions, but concentrations may increase to micromolar levels during disease states (e.g., cirrhosis or endotoxemia). This study tested the hypothesis that high concentrations of SNO-albumin observed in some diseases modulate vascular function and that it acts as a stable reservoir of nitric oxide (NO), releasing this molecule when the concentrations of low-molecular-weight thiols are increased. SNO-albumin was infused into rats to increase the plasma concentration from <50 nmol/l to ∼4 μmol/l. This caused a 29 ± 6% drop in blood pressure, 20 ± 4% decrease in aortic blood flow, and a 25 ± 14% reduction of renal blood flow within 10 min. These observations were in striking contrast to those of an infused arterial vasodilator (hydralazine), which increased aortic blood flow, and suggested that SNO-albumin acts primarily as a venodilator in vivo. This was confirmed by the observations that glyceryl trinitrate (a venodilator) led to similar hemodynamic changes and that the hemodynamic effects of SNO-albumin are reversed by infusion of colloid. Infusion of N-acetylcysteine into animals with artificially elevated plasma SNO-albumin concentrations led to the rapid decomposition of SNO-albumin in vivo and reproduced the hemodynamic effects of SNO-albumin infusion. These data demonstrate that SNO-albumin acts primarily as a venodilator in vivo and represents a stable reservoir of NO that can release NO when the concentrations of low-molecular-weight thiols are elevated.

Differential effect of behavior on cardiac and vasomotor baroreflex responses

1986 ◽  
Vol 251 (1) ◽  
pp. R126-R136 ◽  
Author(s):  
C. A. Combs ◽  
O. A. Smith ◽  
C. A. Astley ◽  
E. O. Feigl
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Peripheral Circulation ◽  
Baroreceptor Reflex ◽  
Aortic Blood Flow ◽  
Renal Vasoconstriction ◽  
Bilateral Carotid Occlusion ◽  
Bilateral Carotid ◽  
Carotid Sinus Baroreflex

Bilateral carotid occlusion was performed in seven baboons during dynamic leg exercise, static arm exercise, feeding, rest, and sleep. The baroreceptor reflex effects on blood pressure, heart rate and interval, renal blood flow, and terminal aortic blood flow were determined during each behavior. The carotid sinus baroreflex increase in blood pressure and heart rate was greatest during sleep and least during exercise. The hindlimb and renal vasomotor responses followed different patterns. The baroreceptor reflex sensitivity for renal vasoconstriction was greatest during rest and least during sleep. The reflex sensitivity in the hindlimb was unaltered by behavior. Thus behavior modifies baroreceptor reflex responses in the heart and peripheral circulation in different patterns.

scholarly journals An Ascending Aortic Haemodynamic Comparison Between Normotensive and Hypertensive Subjects

2018 ◽  
Vol 2 (1) ◽  
pp. 16
Author(s):  
Vijay Kumar Narayana ◽  
Rajeev Sharma ◽  
Niranjan Murthy
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Ejection Fraction ◽  
Pressure Gradient ◽  
Aortic Blood Flow ◽  
Ejection Time ◽  
Acceleration Time ◽  
Aortic Blood ◽  
Ascending Aortic Diameter ◽  
Deceleration Time

<p><strong>Background:</strong> Systemic hypertension, a common disorder with potentially serious complications, exerts ill effects through structural and functional modifications of arterial wall. Haemodynamics play an important role in the development of atherosclerosis. Local hemodynamic temporal pressure and wall shear stress are important for understanding the mechanisms leading to various complications in cardiovascular function.</p><p><strong>Objectives:</strong> Since we could not find such a study in literature involving Indian population, this prompted us to investigate and establish the relationship between the blood pressure and the ascending aortic pulse wave parameters in normal individuals and compare the same with hypertensives.</p><p><strong>Material and Methods:</strong> A case control study was done in a tertiary care hospital involving 25 hypertensive parents and further compared with 25 normotensive subjects of same age group acting as control. The GE ̶ P 100 Doppler echocardiography machine was used to study acceleration time, deceleration time, ejection time, ejection fraction, peak flow velocity and pressure gradient in hypertensives and compared the same with age matched normotensive. Also ascending aortic diameter was mapped at the annulus.</p><p><strong>Results:</strong> The results of our study confirmed our assumption that in hypertensive the ascending aortic haemodynamic parameters are abnormal and both systolic and diastolic blood pressure does exert a statistically significant influence on the Doppler parameters of ascending aorta. The acceleration time, deceleration time, pressure gradient and ejection time showed statistically significant increase in hypertensives when compared to normotensive. At the same time the ejection fraction and the ascending aortic diameter showed a statistically significant decrease than normotensive.</p><p><strong>Conclusion:</strong> We would conclude to say that the Doppler parameters of ascending aortic blood flow are abnormal in hypertensives. This altered haemodynamics may lead to further ill effects by way of altered peripheral haemodynamics. This Doppler evaluation of ascending aortic blood flow can be developed as a clinical tool for evaluating hypertensives and assessing the benefit of treatment of hypertension.</p>

scholarly journals Effects of prolonged reduction in blood flow on submandibular secretory function in anesthetized sheep

2003 ◽  
Vol 95 (2) ◽  
pp. 751-757 ◽  
Author(s):  
A. S. Thakor ◽  
C. N. Brown ◽  
A. V. Edwards
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Salivary Flow ◽  
Secretory Function ◽  
Frequency Dependent ◽  
Aortic Blood ◽  
Aortic Blood Pressure ◽  
Protein Output ◽  
Stimulation Of

Submandibular vascular and secretory responses to parasympathetic chorda-lingual (C-L) stimulation were investigated in anesthetized sheep before, during, and after an intracarotid (ic) infusion of endothelin-1 (ET-1). Stimulation of the peripheral end of the C-L nerve at 4 and 8 Hz produced a frequency-dependent reduction in submandibular vascular resistance (SVR) associated with a frequency-dependent increase in submandibular blood flow, salivary flow, and Na+, K+, and protein output from the gland. During stimulation at 4 Hz, ic ET-1 significantly increased SVR ( P < 0.01), without significantly affecting either the aortic blood pressure or heart rate. Submandibular blood flow (SBF) was reduced by 48 ± 4% and the flow of saliva by 50 ± 1%. The effect on blood and salivary flow persisted for at least 30 min after the infusion of ET-1. The reduction in SBF was associated with a diminution in the output of Na+,K+, and protein in the saliva ( P < 0.01). These effects persisted for 30 min after the infusion of ET-1 had been discontinued and were linearly related to the flow of plasma throughout.

scholarly journals Aging Impairs Renal Autoregulation in Mice

Hypertension ◽  
2020 ◽  
Vol 75 (2) ◽  
pp. 405-412 ◽  
Author(s):  
Jin Wei ◽  
Jinxiu Zhu ◽  
Jie Zhang ◽  
Shan Jiang ◽  
Larry Qu ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Renal Blood Flow ◽  
Tubuloglomerular Feedback ◽  
Myogenic Response ◽  
Renal Autoregulation ◽  
Integrin Α5 ◽  
Aging Kidney

Impaired renal autoregulation permits more transmission of disturbance in systemic blood pressure, which initiates barotrauma in intrarenal microvasculatures such as glomerular and tubulointerstitial capillaries, contributing to the development of kidney damage and deterioration in renal function, especially under the conditions with high blood pressure. Although it has been postulated that autoregulatory efficiency is attenuated in the aging kidney, direct evidence remains lacking. In the present study, we measured the autoregulation of renal blood flow, myogenic response of afferent arteriole (Af-Art), tubuloglomerular feedback in vivo with micropuncture, as well as tubuloglomerular feedback in vitro in isolated perfused juxtaglomerular apparatus in young and aged C57BL/6 mice. We found that renal blood flow was not significantly changed in response to a defined elevation of renal arterial pressure in young mice but significantly increased in aged mice. Additionally, myogenic response of Af-Art measured by microperfusion with a stepwise increase in perfusion pressure was significantly blunted in the aging kidney, which is associated with the attenuation of intraluminal pressure-induced intracellular calcium increases, as well as the reduced expression of integrin α5 (Itga5) in Af-Art. Moreover, both tubuloglomerular feedback in vivo and in vitro were nearly inactive in the aging kidney, which is associated with the significantly reduced expression of adenosine A1 receptor (A1AR) and suppressed vasoconstrictor response to adenosine in Af-Art. In conclusion, this study demonstrates that aging impairs renal autoregulation with blunted myogenic response and inhibited tubuloglomerular feedback response. The underlying mechanisms involve the downregulations of integrin α5 and A1AR in the Af-Art.

Differential effect of T-type voltage-gated Ca2+ channel disruption on renal plasma flow and glomerular filtration rate in vivo

2014 ◽  
Vol 307 (4) ◽  
pp. F445-F452 ◽  
Author(s):  
Anne D. Thuesen ◽  
Henrik Andersen ◽  
Majken Cardel ◽  
Anja Toft ◽  
Steen Walter ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Blood Flow ◽  
Glomerular Filtration Rate ◽  
Glomerular Filtration ◽  
Plasma Flow ◽  
Filtration Rate ◽  
Renal Plasma Flow ◽  
Voltage Gated

Voltage-gated Ca2+ (Cav) channels play an essential role in the regulation of renal blood flow and glomerular filtration rate (GFR). Because T-type Cav channels are differentially expressed in pre- and postglomerular vessels, it was hypothesized that they impact renal blood flow and GFR differentially. The question was addressed with the use of two T-type Cav knockout (Cav3.1−/− and Cav3.2−/−) mouse strains. Continuous recordings of blood pressure and heart rate, para-aminohippurate clearance (renal plasma flow), and inulin clearance (GFR) were performed in conscious, chronically catheterized, wild-type (WT) and Cav3.1−/− and Cav3.2−/− mice. The contractility of afferent and efferent arterioles was determined in isolated perfused blood vessels. Efferent arterioles from Cav3.2−/− mice constricted significantly more in response to a depolarization compared with WT mice. GFR was increased in Cav3.2−/− mice with no significant changes in renal plasma flow, heart rate, and blood pressure. Cav3.1−/− mice had a higher renal plasma flow compared with WT mice, whereas GFR was indistinguishable from WT mice. No difference in the concentration response to K+ was observed in isolated afferent and efferent arterioles from Cav3.1−/− mice compared with WT mice. Heart rate was significantly lower in Cav3.1−/− mice compared with WT mice with no difference in blood pressure. T-type antagonists significantly inhibited the constriction of human intrarenal arteries in response to a small depolarization. In conclusion, Cav3.2 channels support dilatation of efferent arterioles and affect GFR, whereas Cav3.1 channels in vivo contribute to renal vascular resistance. It is suggested that endothelial and nerve localization of Cav3.2 and Cav3.1, respectively, may account for the observed effects.

scholarly journals Estimation of changes in instantaneous aortic blood flow by the analysis of arterial blood pressure

2012 ◽  
Vol 112 (11) ◽  
pp. 1832-1838 ◽  
Author(s):  
Tatsuya Arai ◽  
Kichang Lee ◽  
Robert P. Marini ◽  
Richard J. Cohen
Keyword(s):  
Blood Pressure ◽  
Blood Flow ◽  
Cardiac Output ◽  
Stroke Volume ◽  
Arterial Blood Pressure ◽  
Aortic Blood Flow ◽  
Windkessel Model ◽  
Arx Model ◽  
Arterial Blood ◽  
Aortic Blood

The purpose of this study was to introduce and validate a new algorithm to estimate instantaneous aortic blood flow (ABF) by mathematical analysis of arterial blood pressure (ABP) waveforms. The algorithm is based on an autoregressive with exogenous input (ARX) model. We applied this algorithm to diastolic ABP waveforms to estimate the autoregressive model coefficients by requiring the estimated diastolic flow to be zero. The algorithm incorporating the coefficients was then applied to the entire ABP signal to estimate ABF. The algorithm was applied to six Yorkshire swine data sets over a wide range of physiological conditions for validation. Quantitative measures of waveform shape (standard deviation, skewness, and kurtosis), as well as stroke volume and cardiac output from the estimated ABF, were computed. Values of these measures were compared with those obtained from ABF waveforms recorded using a Transonic aortic flow probe placed around the aortic root. The estimation errors were compared with those obtained using a windkessel model. The ARX model algorithm achieved significantly lower errors in the waveform measures, stroke volume, and cardiac output than those obtained using the windkessel model ( P < 0.05).

Sign in / Sign up

Export Citation Format

Share Document