EFFECT OF THERAPY ON BLOOD VOLUME, BLOOD PRESSURE, AND SPLEEN SIZE IN POLYCYTHEMIA VERA

1. Relationships between labelled albumin disappearance rate (LADR), plasma volume, blood volume, plasma renin activity (PRA) and blood pressure (BP) were studied in normotensive control subjects and patients with hypertension of different aetiology and severity. In essential hypertensive patients without complications an inverse linear relationship was found between blood pressure and plasma or blood volume. 2. Very close inverse correlations were found between LADR and PRA in both normotensive subjects and patients with uncomplicated essential hypertension. LADR appears to be an excellent reference standard for PRA. 3. It is postulated that LADR mainly reflects the relation between circulating fluid and vascular capacitance tone. LADR is increased in hypertension and blood volume may still be inappropriately high.

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Interstitial Correction of Blood Volume Decrease during Hemodialysis

The International Journal of Artificial Organs ◽

10.1177/039139888901201005 ◽

1989 ◽

Vol 12 (10) ◽

pp. 626-631 ◽

Cited By ~ 12

Author(s):

P.M. Kouw ◽

P.M.J.M. De Vries ◽

P.L Oe

Keyword(s):

Blood Pressure ◽

Blood Volume ◽

Extracellular Fluid ◽

Compensatory Mechanism ◽

Fluid Shift ◽

Lower Blood ◽

Volume Blood ◽

Dialysate Sodium ◽

Volume Decrease

The etiology of hypotension during hemodialysis is multifactorial. Probably a decrease in blood volume caused by ultrafiltration, and acetate are both involved, while refilling from the interstitium acts as a compensatory mechanism. An osmotically induced transcellular fluid shift to intracellular might reduce the refilling capacity. This study investigated the effect of ultrafiltration on blood volume, blood pressure and refilling. The role of acetate and blood volume decrease in hypotension was established and intra- and extracellular fluid changes were calculated. Blood volume decrease depended on ultrafiltration: at high ultrafiltration rates refilling failed, apparently more so at high acetate plasma levels. An isolated blood volume decrease did not lower blood pressure. Concomitant high acetate levels caused hypotension and also seemed to reduce refilling. Nearly all refilling fluid came from the extracelullar compartment. Only high dialysate sodium concentrations gave rise to an intracellular loss.

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Neuroendocrine control of blood volume, blood pressure and cardiovascular function in horses

Equine Veterinary Journal ◽

10.1111/j.2042-3306.1995.tb04894.x ◽

2010 ◽

Vol 27 (S18) ◽

pp. 77-81 ◽

Cited By ~ 4

Author(s):

K. H. McKEEVER ◽

K. W. HINCHCLIFF

Keyword(s):

Blood Pressure ◽

Blood Volume ◽

Cardiovascular Function ◽

Neuroendocrine Control ◽

Volume Blood

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Blood volume, blood pressure and total body sodium: internal signalling and output control

Acta Physiologica ◽

10.1111/j.1748-1716.2008.01932.x ◽

2009 ◽

Vol 195 (1) ◽

pp. 187-196 ◽

Cited By ~ 36

Author(s):

P. Bie

Keyword(s):

Blood Pressure ◽

Blood Volume ◽

Output Control ◽

Body Sodium ◽

Volume Blood ◽

Total Body

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Positive and Negative Aspects of Sodium Intake in Dialysis and Non-Dialysis CKD Patients

Nutrients ◽

10.3390/nu13030951 ◽

2021 ◽

Vol 13 (3) ◽

pp. 951

Author(s):

Yasuyuki Nagasawa

Keyword(s):

Blood Pressure ◽

Nutritional Status ◽

Water Intake ◽

Salt Intake ◽

Sodium Intake ◽

Extracellular Fluid ◽

Sodium Restriction ◽

Dialysis Patients ◽

Positive Effects ◽

Volume Blood

Sodium intake theoretically has dual effects on both non-dialysis chronic kidney disease (CKD) patients and dialysis patients. One negatively affects mortality by increasing proteinuria and blood pressure. The other positively affects mortality by ameliorating nutritional status through appetite induced by salt intake and the amount of food itself, which is proportional to the amount of salt under the same salty taste. Sodium restriction with enough water intake easily causes hyponatremia in CKD and dialysis patients. Moreover, the balance of these dual effects in dialysis patients is likely different from their balance in non-dialysis CKD patients because dialysis patients lose kidney function. Sodium intake is strongly related to water intake via the thirst center. Therefore, sodium intake is strongly related to extracellular fluid volume, blood pressure, appetite, nutritional status, and mortality. To decrease mortality in both non-dialysis and dialysis CKD patients, sodium restriction is an essential and important factor that can be changed by the patients themselves. However, under sodium restriction, it is important to maintain the balance of negative and positive effects from sodium intake not only in dialysis and non-dialysis CKD patients but also in the general population.

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Resonance in a mathematical model of baroreflex control: arterial blood pressure waves accompanying postural stress

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.00050.2004 ◽

2005 ◽

Vol 288 (6) ◽

pp. R1637-R1648 ◽

Cited By ~ 36

Author(s):

Peter E. Hammer ◽

J. Philip Saul

Keyword(s):

Blood Pressure ◽

Mathematical Model ◽

Blood Volume ◽

Low Frequency ◽

Pressure Waves ◽

Central Blood Volume ◽

Arterial Baroreflex ◽

Arterial Blood ◽

Gain Margin ◽

The Stability

A mathematical model of the arterial baroreflex was developed and used to assess the stability of the reflex and its potential role in producing the low-frequency arterial blood pressure oscillations called Mayer waves that are commonly seen in humans and animals in response to decreased central blood volume. The model consists of an arrangement of discrete-time filters derived from published physiological studies, which is reduced to a numerical expression for the baroreflex open-loop frequency response. Model stability was assessed for two states: normal and decreased central blood volume. The state of decreased central blood volume was simulated by decreasing baroreflex parasympathetic heart rate gain and by increasing baroreflex sympathetic vaso/venomotor gains as occurs with the unloading of cardiopulmonary baroreceptors. For the normal state, the feedback system was stable by the Nyquist criterion (gain margin = 0.6), but in the hypovolemic state, the gain margin was small (0.07), and the closed-loop frequency response exhibited a sharp peak (gain of 11) at 0.07 Hz, the same frequency as that observed for arterial pressure fluctuations in a group of healthy standing subjects. These findings support the theory that stresses affecting central blood volume, including upright posture, can reduce the stability of the normally stable arterial baroreflex feedback, leading to resonance and low-frequency blood pressure waves.

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