The effect of changes in blood volume on low frequency blood pressure fluctuations in spontaneously hypertensive rats

2003 ◽  
Author(s):  
O. Oz ◽  
S. Eliash ◽  
S. Cohen ◽  
S. Akselrod
Keyword(s):  
Blood Pressure ◽  
Blood Volume ◽  
Spontaneously Hypertensive Rats ◽  
Pressure Fluctuations ◽  
Low Frequency ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

Blood pressure control and erythrocytosis in rats: theory and observations

1994 ◽  
Vol 72 (6) ◽  
pp. 679-686 ◽  
Author(s):  
Anne B. Gould ◽  
Susan Goodman ◽  
Charles Swartz
Keyword(s):  
Blood Pressure ◽  
Cell Volume ◽  
Blood Volume ◽  
Packed Cell Volume ◽  
Spontaneously Hypertensive Rats ◽  
Plasma Renin ◽  
Pressure Control ◽  
Peripheral Vascular ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive

We compared some of our latest experiments on blood pressure control and erythrocytosis in spontaneously hypertensive rats with Gaar's computer-simulated studies, which suggest that erythrocytosis is a key to understanding the hemodynamic changes in hypertension. We tested two of Gaar's several predictions: (i) peripheral vascular resistance decreases when the feedback control of erythrocytosis is blocked and (ii) in primary hypertension, blood volume is increased slightly. We also studied the interrelation of systolic blood pressure and plasma renin substrate in spontaneously hypertensive rats, and the effect of diet on renin, blood pressure, and erythrocytosis. Our data showed that (i) on a percentage basis the renin system supports blood pressure essentially in the same manner in normal and hypertensive rats, (ii) peripheral vascular resistance decreased when erythrocytosis was partially blocked by feeding a low-iron diet, (iii) blood volume was similar in normal and hypertensive rats, and (iv) dextrin stimulates plasma renin, packed cell volume, and blood pressure in hypertensive rats. We conclude that blood pressure and erythrocytosis are interrelated, that the combined data of simulated and experimental studies support the notion that primary hypertension is a blood-vessel adaptation in response to a renal energy need that may require additional oxygen.Key words: angiotensinogen, renin, dextrin, packed cell volume.

scholarly journals Effects of Chronic Cholinergic Stimulation Associated With Aerobic Physical Training on Cardiac Morphofunctional and Autonomic Parameters in Spontaneously Hypertensive Rats

2021 ◽  
Author(s):  
Camila B. Gardim ◽  
Ana Catarine V. Oliveira ◽  
Bruno Augusto Aguilar ◽  
Stella V. Philbois ◽  
Hugo C. D. Souza
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Physical Training ◽  
Spontaneously Hypertensive Rats ◽  
Low Frequency ◽  
Pyridostigmine Bromide ◽  
Cholinergic Stimulation ◽  
Hypertensive Rats ◽  
Spontaneously Hypertensive ◽  
Pharmacological Blockade

Abstract We investigated in spontaneously hypertensive rats (SHR) the hemodynamic, cardiac morphofunctional, and cardiovascular autonomic adaptations after a protocol of aerobic physical training associated with chronic cholinergic stimulation. Fifty-four SRH were divided into two groups: trained and untrained. Afterward, each group was subdivided into three smaller groups: vehicle, treated with pyridostigmine bromide at 5mg/kg/day, and at 15mg/kg/day. The following protocols were assessed: echocardiography, autonomic double pharmacological blockade, analysis of heart rate variability (HRV), blood pressure variability (BPV), and baroreflex sensitivity (BRS). Physical training and pyridostigmine bromide reduced blood pressure and heart rate and increased vagal participation in cardiac tonic autonomic balance. Associated the responses were potentialized. Pyridostigmine bromide increased the oscillation of low frequency (LF:0.2-0.75Hz) and high frequency (HF:0.75-3Hz) of HRV. However, the association with physical training attenuated HF oscillations. Pyridostigmine bromide also increased LF oscillations of BPV. Both treatments promoted morphofunctional adaptations and associated increased the ejection volume, ejection fraction, cardiac output, and cardiac index. In conclusion, the association of pyridostigmine bromide and physical training promoted greater benefits in hemodynamic parameters and increase vagal influence on cardiac autonomic tonic balance. Nonetheless, pyridostigmine bromide alone seems to negatively affect BPV, while the association of treatment negatively influences HRV.

An experimental study in reducing blood pressure in spontaneously hypertensive rats through extracellular signal-regulated kinase inhibition

2010 ◽  
Vol 34 (8) ◽  
pp. S31-S31
Author(s):  
Li Jing ◽  
Jian‑zhong Zhang ◽  
Jin‑ping Sun ◽  
Xin An ◽  
Feng‑ying Guo ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Experimental Study ◽  
Spontaneously Hypertensive Rats ◽  
Hypertensive Rats ◽  
Kinase Inhibition ◽  
Spontaneously Hypertensive ◽  
Extracellular Signal Regulated Kinase ◽  
Extracellular Signal
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