Spontaneous variations in arterial blood pressure, heart rate and sympathetic nerve activity in conscious normotensive and spontaneously hypertensive rats

1984 ◽  
Vol 120 (4) ◽  
pp. 595-600 ◽  
Author(s):  
S.-E. RICKSTEN ◽  
STEFAN LUNDIN ◽  
PETER THOREN
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Sympathetic Nerve ◽  
Spontaneously Hypertensive Rats ◽  
Sympathetic Nerve Activity ◽  
Hypertensive Rats ◽  
Nerve Activity ◽  
Spontaneously Hypertensive ◽  
Arterial Blood

scholarly journals Exacerbated pressor and sympathoexcitatory effects of central Elabela in spontaneously hypertensive rats

2020 ◽  
Vol 318 (1) ◽  
pp. H124-H134 ◽  
Author(s):  
Zhi Geng ◽  
Chao Ye ◽  
Ying Tong ◽  
Feng Zhang ◽  
Ye-Bo Zhou ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sympathetic Nerve ◽  
Spontaneously Hypertensive Rats ◽  
Sympathetic Nerve Activity ◽  
Akt Pathway ◽  
Sympathetic Activation ◽  
Hypertensive Rats ◽  
Nerve Activity ◽  
Vasopressin Release ◽  
Spontaneously Hypertensive

Elabela (ELA) is a newly discovered peptide that acts as a novel endogenous ligand of angiotensin receptor-like 1 (APJ) receptor. This study was designed to evaluate the effects of ELA-21 in paraventricular nucleus (PVN) on blood pressure and sympathetic nerve activity in spontaneously hypertensive rats (SHR). Experiments were performed in male Wistar-Kyoto rats (WKY) and SHR. ELA expression was upregulated in PVN of SHR. PVN microinjection of ELA-21 increased renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP), heart rate (HR), plasma norepinephrine, and arginine vasopressin (AVP) levels in SHR. Intravenous injection of ELA-21 significantly decreased MAP and HR in both WKY and SHR, but only induced a slight decrease in RSNA. APJ antagonist F13A in PVN abolished the effects of ELA-21 on RSNA, MAP and HR. Intravenous infusion of both ganglionic blocker hexamethonium and AVP V1a receptor antagonist SR49059 caused significant reduction in the effects of ELA-21 on RSNA, MAP and HR in SHR, while combined administration of hexamethonium and SR49059 abolished the effects of ELA-21. ELA-21 microinjection stimulated Akt and p85α subunit of phosphatidylinositol 3-kinase (PI3K) phosphorylation in PVN, whereas PI3K inhibitor LY294002 or Akt inhibitor MK-2206 almost abolished the effects of ELA-21 on RSNA, MAP, and HR. Chronic PVN infusion of ELA-21 induced sympathetic activation, hypertension, and AVP release accompanied with cardiovascular remodeling in normotensive WKY. In conclusion, ELA-21 in PVN induces exacerbated pressor and sympathoexcitatory effects in hypertensive rats via PI3K-Akt pathway. NEW & NOTEWORTHY We demonstrated that PVN microinjection of ELA-21 increases sympathetic nerve activity and blood pressure, which can be abolished by pretreatment of APJ antagonist. This is the first demonstration that central ELA can induce hypertension. The pressor effects in PVN are mediated by both sympathetic activation and vasopressin release via PI3K-Akt pathway. Our data confirm that ELA is upregulated in the PVN of SHR and so may be involved in the pressor and sympathoexcitatory effects in hypertension.

scholarly journals Hypotensive and Bradycardic Effects of Quinovic Acid Glycosides from Aspidosperma fendleri in Spontaneously Hypertensive Rats

2015 ◽  
Vol 10 (2) ◽  
pp. 1934578X1501000 ◽  
Author(s):  
Omar Estrada ◽  
Juan M. González-Guzmán ◽  
María M. Salazar-Bookman ◽  
Alfonso Cardozo ◽  
Eva Lucena ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Mean Arterial Blood Pressure ◽  
Spontaneously Hypertensive Rats ◽  
Cardiovascular Effects ◽  
Hypertensive Rats ◽  
Triterpenoid Saponins ◽  
Spontaneously Hypertensive ◽  
Arterial Blood

The Aspidosperma genus (Apocynaceae) represents one of the largest sources of indole alkaloids widely associated with cardiovascular effects. Aspidosperma fendleri, a plant found mainly in Venezuela, has a single phytochemical report in which is revealed the presence of alkaloids in its seeds. This study explored the cardiovascular effects of an ethanolic extract of A. fendleri leaves (EEAF) in spontaneously hypertensive rats (SHR) and its potential bioactive compounds. Using bioguided fractionation, fractions and pure compounds were intravenously administered to SHR and their effects on mean arterial blood pressure (MABP) and heart rate (HR) monitored over time. EEAF induced hypotensive and bradycardic effects as shown by significant reductions in mean arterial blood pressure (MABP) and heart rate (HR), respectively. Bioactivity-guided fractionation led to the isolation of a mixture of two known isomeric triterpenoid glycosides identified by spectral evidence as quinovic acid 3- O-β-rhamnopyranoside and quinovic acid 3- O-β-fucopyranoside. This mixture of triterpenoid saponins induced reductions in MABP and HR similar to those induced by propranolol. Together, these findings indicate that the two quinovic acid glycosides are responsible for the hypotensive and bradycardic effects which suggest their potential use in cardiovascular therapy.

scholarly journals The Effect of Propranolol on Blood Pressure and Sympathetic Nerve Activity in the Spontaneously Hypertensive Rats

1980 ◽  
Vol 21 (4) ◽  
pp. 563-563 ◽  
Author(s):  
Kasuo Takeda ◽  
Susumu Sasaki ◽  
Isao Kaimasu ◽  
Manabu Yoshimura ◽  
Masao Nakagawa ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Sympathetic Nerve ◽  
Spontaneously Hypertensive Rats ◽  
Sympathetic Nerve Activity ◽  
Hypertensive Rats ◽  
Nerve Activity ◽  
Spontaneously Hypertensive

Nitric oxide within the paraventricular nucleus mediates changes in renal sympathetic nerve activity

1997 ◽  
Vol 273 (3) ◽  
pp. R864-R872 ◽  
Author(s):  
K. Zhang ◽  
W. G. Mayhan ◽  
K. P. Patel
Keyword(s):  
Nitric Oxide ◽  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Nerve Activity ◽  
Renal Sympathetic Nerve ◽  
Arterial Blood ◽  
Renal Sympathetic

The paraventricular nucleus (PVN) of the hypothalamus is known to be involved in the control of sympathetic outflow. The goal of the present study was to examine the role of nitric oxide within the PVN in the regulation of renal sympathetic nerve activity. Renal sympathetic nerve discharge (RSND), arterial blood pressure, and heart rate in response to the microinjection of nitric oxide synthase inhibitor NG-monomethyl-L-arginine (L-NMMA; 50, 100, and 200 pmol) into the PVN were measured in male Sprague-Dawley rats. Microinjection of L-NMMA elicited an increase in RSND, arterial blood pressure, and heart rate. Administration of NG-monomethyl-D-arginine (D-NMMA, 50-200 pmol) into the PVN did not change RSND, arterial pressure, or heart rate. Similarly, microinjection of another nitric oxide inhibitor NG-nitro-L-arginine methyl ester (L-NAME; 100 nmol) also elicited an increase in RSND, arterial blood pressure, and heart rate. L-Arginine (100 nmol) reversed the effects of L-NAME in the PVN. Furthermore, microinjection of sodium nitroprusside (SNP; 50, 100, and 200 nmol) into the PVN elicited a significant decrease in RSND, arterial blood pressure, and heart rate. These effects of L-NMMA, L-NAME, and SNP on RSND and arterial blood pressure were not mediated by their vasoactive action because microinjection of phenylephrine and hydralazine did not elicit similar respective changes. In conclusion, our data indicate that endogenous nitric oxide within the PVN regulates sympathetic outflow via some inhibitory mechanisms. Altered nitric oxide mechanisms within the PVN may contribute to elevated sympathetic nerve activity observed during various diseases states such as heart failure and hypertension.

Hyperoxia lowers sympathetic activity at rest but not during exercise in humans

1991 ◽  
Vol 260 (5) ◽  
pp. R873-R878 ◽  
Author(s):  
D. R. Seals ◽  
D. G. Johnson ◽  
R. F. Fregosi
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Arterial Blood Pressure ◽  
Sympathetic Nerve ◽  
Sympathetic Nerve Activity ◽  
Total Activity ◽  
Burst Frequency ◽  
Nerve Activity ◽  
Arterial Blood ◽  
Exercise In Humans

The primary aim of this study was to determine the influence of systemic hyperoxia on sympathetic nervous system behavior at rest and during submaximal exercise in humans. In seven healthy subjects (aged 19-31 yr) we measured postganglionic sympathetic nerve activity to skeletal muscle (MSNA) in the leg, antecubital venous norepinephrine concentrations, heart rate, and arterial blood pressure during normoxic rest (control) followed by 3- to 4-min periods of either hyperoxic (100% O2 breathing) rest, normoxic exercise (rhythmic handgrips at 50% of maximum force), or hyperoxic exercise. During exercise, isocapnia was maintained by adding CO2 to the inspirate as necessary. At rest, hyperoxia lowered MSNA burst frequency (12-42%) and total activity (6-42%) in all subjects; the average reductions were 25 and 23%, respectively (P less than 0.05 vs. control). Heart rate also decreased during hyperoxia (6 +/- 1 beats/min, P less than 0.05), but arterial blood pressure was not affected. During hyperoxic compared with normoxic exercise, there were no differences in the magnitudes of the increases in MSNA burst frequency or total activity, plasma norepinephrine concentrations, or mean arterial blood pressure. In contrast, the increase in heart rate during hyperoxic exercise (13 +/- 2 beats/min) was less than the increase during normoxic exercise (20 +/- 2 beats/min; P less than 0.05). We conclude that, in healthy humans, systemic hyperoxia 1) lowers efferent sympathetic nerve activity to skeletal muscle under resting conditions without altering venous norepinephrine concentrations and 2) has no obvious modulatory effect on the nonactive muscle sympathetic nerve adjustments to rhythmic exercise.

Sign in / Sign up

Export Citation Format

Share Document