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During ten exchange transfusions, the infant's gain or loss of haemoglobin, and of the volumes of red cells and plasma were studied quantitatively The gain or loss of haemoglobin was found to be closely correlated to the difference between the haemoglobin concentration of the given blood and that of the infant before the exchange transfusion. The standard ACD-blood used was hypo-osmolar (NIH sol. B) and its red cells overhydrated. During the exchange, the cells returned to normal and released water, about 10 ml per kg of the infant's bodyweight. Haematocrit readings therefore are unsuitable for the judgement of the ACD donor blood's oxygen transport capacity. As a rule, less plasma was given than removed. However, if the above-mentioned water, released from the red cells, was included in the "given" volume, the latter became almost equal to the volume removed.
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Total and central plasma volume was measured in 51 male offspring of hypertensive individuals belonging to families with a history of essential hypertension for at least two generations. They were compared to 38 age-matched individuals without known hypertension in their families for at least two generations. Central plasma volume was determined at rest and during muscle work, cold pressure test and psychological stress. The offspring had significantly lower total plasma volume than the controls. Central plasma volume was equal in offspring and controls. The quotient central/total plasma volume was thus higher in offspring than in controls, and the difference was statistically significant during psychological stress and dynamic muscle work. Possible reasons for the differences between offspring and controls are an increased transcapillary escape of plasma, an increased quotient intracellular/extracellular fluid and/or increased tone of the capacitance vessels.
Influence of hypothalamically induced emotional behavior on the circulating plasma volume, plasma levels of glucose, epinephrine (E), norepinephrine (NE), dopamine (DA) and cortisol were examined in awake cats under both fasted and fed conditions. Restlessness was evoked intermittently for 6 h by electrical stimulation of the anteromedial hypothalamus (AMH). Blood was sampled immediately before, 1 h after and 6 h after the start of stimulation. Changes in the plasma volume was calculated by changes of hemoglobin (Hb) and hematocrit (Ht). As the control group, another 7 cats with electrodes implanted but unstimulated were identically treated under both fasted and fed conditions. Both E and glucose levels in restlessness group once markedly increased after 1 h and then tended to decrease after 6 h, whereas NE levels in restlessness group increased after 1 h and further increased after 6 h, whether cats were fasted or fed. DA levels increased under the fasted condition of restlessness. The cortisol level markedly increased in both fasted and fed restlessness groups. The plasma volume in control group increased under the fed condition, while in restlessness group it decreased remarkably and tended to decrease more in a fasted state than in a fed state. These results indicated that AMH induced restlessness elicited marked sympatho-adrenal activation, hyperglycemia and hemoconcentration, whether cats were fasted or fed. Relationship among such responses, and the difference in responses between fasted and fed conditions were also discussed in the paper.
In order to determine the relationship between reductions in body weight, body volume, and plasma volume, 22 track runners underwent exercises of various intensities and durations. The average mileage performed in the distance runs was 8.4 miles. The average caloric cost was 822 and 288 Cal for the distance and sprint activities, respectively. The overall range of energy expenditure was 100 to 1000 Cal. Before and after the workbout, body volume and density were determined by hydrostatic weighing on each subject. In addition, venous blood samples were analyzed for hematocrit (Hct) and hemoglobin (Hb), and the percent change in plasma volume (% delta PV) was calculated. Body weight and body volume decreases occurred in all subjects. Body density, percent body fat, and plasma volume were significantly altered only in the group of athletes undergoing distance runs. Body weight loss ranged from 0.3 kg to 2.0 kg and was correlated with body volume decreases (r = 0.91) and energy expended (r = 0.73). Body volume changes were related to the extent of density increases (r = 0.58), changes in plasma volume (r = 0.53), and energy enpended (r = 0.75). The % delta PV was significantly related only to changes in body volume. The results of this study indicate that acute exercise does affect body volume and thus the density and % fat determinations. These changes do not parallel closely the changes in plasma volume. The data suggest that for absolute accuracy, the state of hydration of the subject should be controlled prior to hydrostatic weighing. However, even in dehydration caused by prolonged distance running, the density measurement error is small and nearly within the methodological error of the hydrostatic weighing technique.
The knowledge of plasma volume (PV) is a basic requirement for the standardization of plasma exchange therapy. PV has to be determined by calculation, as the measurement of PV before every plasma exchange is too cost- and time consuming. A known correlation with measured values results from calculation of plasma volume by means of patient's height and weight. But the present equations are only reliable at normal hematocrit. For this reason we modified the Retzlaff-equations and compared the validity of plasma volume predictions, calculated by these and own equations, with plasma volume measured by the 51Cr-method in 59 patients with pathological hematocrit. The correlation coefficient was 0.82 for men and 0.81 for women (2 0.001) with the modified Retzlaff-equations. On the average the relative error was -1.5% for all and 2.8% for fat and thin men. No significant improvement of accuracy was achieved with other equations. Thus, plasma volume can accurately be calculated from height, weight, and hematocrit with our modified Retzlaff-equations in patients with pathological hematocrit, even if they are very fat or thin. Nomograms for men and women were constructed in order to facilitate the calculation.
Four females were studied during a 10-day heat acclimation regimen consisting of 2 h per day of stationary cycle riding (means = 46% VO2 max) in a hot environment (40 degrees C, 50% RH) to determine the effects of heat acclimation on changes in plasma volume and vascular protein both at rest and during exercise. Changes in plasma volume were calculated from hematocrit and hemoglobin measurements. Plasma volume decreased during each 2-h session on baseline days through heat day 6 (-4.9% to -1.2%). On heat days 8 and 10, there was an expansion of plasma volume during the session (1.4% and 0.8%). This hemodilution was significantly different (P less than 0.05) from the hemoconcentration on baseline through heat day 4. The gain of protein during the 2-h session was not significantly different on any of the heat days from that on baseline days. With acclimation of females to work in the heat, there is an increased ability to maintain the fluid of the vascular compartment during a 2-h exercise session in the heat.
Plasma volume, hematocrit, protein and electrolyte concentrations in plasma were measured in control and water-deprived rats every three days after starting the experiment until the 15th day. Plasma volume variations, as related to body weight, suggest that water loss from plasma was proportional to total body water at three days and after 9 days of water deprivation. Greater plasma water than body water loss was found during the period between 3 and 9 days. Plasma protein and electrolyte variations suggest that during water deprivation there is a loss of protein, sodium and potassium from plasma, which is proportionally less than that of plasma water. Potassium, calcium and inorganic phosphorus were lost proportionally to plasma water. The variations in plasma volume changes were partially explained as due to variations in plasma protein and electrolyte concentrations.
1. Rats with indwelling aortic and right atrial cannulae were maintained on a sodium-free diet before and after renal arterial constriction combined with contralateral nephrectomy. Control animals underwent the same protocol except that non-constricting clips were used. 2. Plasma volumes in the salt-deprived animals were lower than previously determined values in animals with free access to sodium. After clipping plasma volume increased in the hypertensive animals. Extracellular fluid volume was increased equally in both normotensive and hypertensive animals on the second postoperative day only. 3. Before clipping and contralateral nephrectomy plasma angiotensin II values were higher than normal. After the operation angiotensin II concentrations fell to normal over a period of 14 days without significant differences between experimental and control groups. 4. It is concluded that high blood pressure after clipping may be in part maintained by increases in plasma volume. However, the results strongly suggest that other renal mechanisms are likely to be of major pathogenic importance.
Plasma volumes, blood volumes, and plasma total protein, albumin, and bilirubin concentrations have been determined in rats for 72 h following 20 or 40 mL kg-1 haemodilution with Fluosol-DA or 0.9% NaCl. Haemodilution with 20 mL kg-1 of either haemodiluent had no influence on the measured values. Plasma and blood volumes did not change after Fluosol-DA haemodilution at 40 mL kg-1, but albumin and bilirubin concentrations were decreased for 72 h. Only bilirubin concentrations were decreased for 72 h following haemodilution with 40 mL kg-1 of 0.9% NaCl. It was concluded that changes in a drug's plasma protein binding, and not the plasma or blood volume, are responsible for the reported alterations in a drug's apparent volume of distribution after haemodilution.
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A method is described for frequent sequential blood volume estimation in baboons using 32P for red cell volume measurements and 125I-albumin for simultaneous plasma volume measurements. Values for red cell, plasma, and total blood volumes are reported. Close correlations of the volumes to bodyweight were demonstrated. Circulatory half-lives of the isotopes, determined from disappearance curves, confirmed their suitability for serial measurements in these baboons.