Influence of hydrostatic pressure gradients on regulation of plasma volume after exercise

1998 ◽  
Vol 85 (2) ◽  
pp. 667-675 ◽  
Author(s):  
Gary W. Mack ◽  
Roger Yang ◽  
Alan R. Hargens ◽  
Kei Nagashima ◽  
Andrew Haskell
Keyword(s):  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Plasma Volume ◽  
Fluid Pressure ◽  
Colloid Osmotic Pressure ◽  
Upright Position ◽  
Upright Posture ◽  
Immediate Recovery ◽  
Before And After ◽  
The Impact

The impact of posture on the immediate recovery of intravascular fluid and protein after intense exercise was determined in 14 volunteers. Forces which govern fluid and protein movement in muscle interstitial fluid pressure (PISF), interstitial colloid osmotic pressure (COPi), and plasma colloid osmotic pressure (COPp) were measured before and after exercise in the supine or upright position. During exercise, plasma volume (PV) decreased by 5.7 ± 0.7 and 7.0 ± 0.5 ml/kg body weight in the supine and upright posture, respectively. During recovery, PV returned to its baseline value within 30 min regardless of posture. PV fell below this level by 60 and 120 min in the supine and upright posture, respectively ( P < 0.05). Maintenance of PV in the upright position was associated with a decrease in systolic blood pressure, an increase in COPp (from 25 ± 1 to 27 ± 1 mmHg; P < 0.05), and an increase in PISF (from 5 ± 1 to 6 ± 2 mmHg), whereas COPi was unchanged. Increased PISFindicates that the hydrostatic pressure gradient favors fluid movement into the vascular space. However, retention of the recaptured fluid in the plasma is promoted only in the upright posture because of increased COPp.

Tissue pressure and plasma oncotic pressure during exercise

1984 ◽  
Vol 56 (1) ◽  
pp. 102-108 ◽  
Author(s):  
V. Mohsenin ◽  
R. R. Gonzalez
Keyword(s):  
Osmotic Pressure ◽  
Plasma Volume ◽  
Interstitial Fluid ◽  
Vastus Lateralis ◽  
Fluid Pressure ◽  
Colloid Osmotic Pressure ◽  
Interstitial Fluid Pressure ◽  
Plasma Sodium ◽  
Vastus Lateralis Muscle ◽  
Base Line

Six healthy male subjects exercised on a cycle ergometer for 3 min for assessment of forces involved in transvascular fluid shift during intense exercise. The work load was at 105% of peak O2 uptake of the subjects. This caused a 17.2 +/- 1.2% reduction in plasma volume. The plasma volume loss was associated with an increase in plasma sodium, from 142.6 +/- 0.5 to 148.1 +/- 1.0 meq X 1(-1) (P less than 0.005); chloride, from 101.8 +/- 0.6 to 104.6 +/- 0.9 meq X 1(-1) (P less than 0.005); lactate, from 1.4 +/- 0.2 to 14.0 +/- 1.5 meq X 1(-1) (P less than 0.005); and osmolality, from 283 +/- 2 to 299 +/- 3 mosmol X kg-1 H2O (P less than 0.005) within 2 min after cessation of exercise. Plasma protein increased from 7.0 +/- 0.2 to 8.1 +/- 0.3 g X dl-1 (P less than 0.005), and plasma colloid osmotic pressure from 25.1 +/- 0.6 to 30.6 +/- 1.4 mmHg (P less than 0.005) after exercise. Interstitial fluid pressure in the exercising vastus lateralis muscle increased from a base-line value (SE) of -1.0 +/- 0.9 to + 1.5 +/- 1.1 cmH2O, 14 min after the end of exercise (P less than 0.05). Interstitial fluid pressure of the triceps brachii (inactive) did not change significantly after exercise. Our data suggest that increased transvascular colloid osmotic pressure and elevation of interstitial fluid pressure become increasingly important in preventing loss of plasma volume during maximal exercise.

Transcapillary Starling forces using membrane osmometry

1980 ◽  
Vol 238 (6) ◽  
pp. H886-H888
Author(s):  
J. L. Christian ◽  
R. A. Brace
Keyword(s):  
Osmotic Pressure ◽  
Interstitial Fluid ◽  
Subcutaneous Tissue ◽  
Fluid Pressure ◽  
Colloid Osmotic Pressure ◽  
Interstitial Fluid Pressure ◽  
Tissue Samples ◽  
Small Pore ◽  
The Difference ◽  
Good Agreement

Membrane osmometry was used to estimate the four transcapillary Starling pressures in subcutaneous tissue of rats, guinea pigs, and dogs. Isolated subcutaneous tissue samples were either placed on a large-pore or small-pore osmometer that measured the interstitial fluid pressure (Pif) and the difference between the interstitial fluid pressure and the interstitial protein osmotic pressure (Pif-pi if), respectively. The colloid osmotic pressure of the interstitial fluid (pi if) was obtained from the difference in these two pressures. A plasma sample placed on the small-pore osmometer yielded the colloid osmotic pressure of the plasma proteins (pi c). Finally the capillary pressure (Pc) was calculated from the three other Starling forces. In the rat, guinea pig, and dog, respectively, the estimated Starling forces were as follows: Pif -2.2, -2.1, and -4.8 mmHg; pi if, 7.3, 4.8, and 4.4 mmHg; pi c, 21.3, 19.5, and 19.2 mmHg; and Pc, 11.8, 12.6, and 10.0 mmHg. A comparison with data obtained in other studies using different methods shows good agreement and strongly supports membrane osmometry as a method for measuring the Starling pressures in subcutaneous tissue.

Functional characteristics of the renal interstitium

1981 ◽  
Vol 241 (2) ◽  
pp. F105-F111 ◽  
Author(s):  
M. Wolgast ◽  
M. Larson ◽  
K. Nygren
Keyword(s):  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Plasma Proteins ◽  
Protein Transport ◽  
Fluid Transport ◽  
Colloid Osmotic Pressure ◽  
Capillary Membrane ◽  
Tubular Transport ◽  
Physical Forces ◽  
Capillary Fluid

The renal interstitial space analyzed as "inulin space" comprises about 13% in the rat. The Starling forces of this compartment are governed by the balance between tubular and capillary fluid transport and also by the leakage of plasma proteins from the blood side. Protein transport will occur in a large-pore system in the peritubular capillary membrane. During control antidiuresis, the interstitial hydrostatic pressure is 2-4 mmHg. The colloid osmotic pressure shows a larger variability but is generally about 5 mmHg. During conditions of depressed capillary reabsorption but unchanged tubular reabsorption, as in saline expansion, the interstitial hydrostatic pressure rises 3-4 times, whereas the colloid osmotic pressure will show a steep fall resulting from the increased fluid entry and unchanged protein transport. The interstitial volume increases only slightly, since it is compressed by the expanding tubules. The influence of interstitial physical forces on tubular transport remains unclear, mainly due to the inaccessibility of the lateral interspaces to direct measurement of relevant parameters.

scholarly journals The Mechanism of Urine Formation in Invertebrates

1936 ◽  
Vol 13 (3) ◽  
pp. 309-328
Author(s):  
L. E. R. PICKEN
Keyword(s):  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Body Fluid ◽  
External Medium ◽  
Carcinus Maenas ◽  
Colloid Osmotic Pressure ◽  
Body Fluids ◽  
The Body ◽  
Small Animals ◽  
Urine Formation

1. In Carcinus maenas: (a) The blood may be hypertonic, isotonic or hypotonic to the external medium. (b) The urine may be hypertonic, isotonic or hypotonic to the blood, and its concentration may differ in the two antennary glands. (c) The hydrostatic pressure of the body fluid is c. 13 cm. of water. (d) The colloid osmotic pressure of the blood is c. 11 cm. of water. (e) The urine probably contains protein and has a colloid osmotic pressure of c. 3 cm. of water. 2. In Potamobius fluviatilis: (a) The blood is hypertonic to the external medium. (b) The urine is hypotonic to the blood but hypertonic to the external medium and its concentration may differ in the two antennary glands. (c) The hydrostatic pressure of the body fluid is c. 20 cm. of water. (d) The colloid osmotic pressure of the blood is c. 15 cm. of water. (e) The urine may contain protein and has a colloid osmotic pressure (calculated) of c. 2 cm. of water. 3. In Peripatopsis spp.: (a) The blood is hypertonic to the urine. (b) The hydrostatic pressure of the body fluid is c. 10 cm. of water. (c) The colloid osmotic pressure (calculated) of the blood is c. 5 cm. of water. (d) The urine may contain protein and has a colloid osmotic pressure (calculated) of c. 2.5 cm. of water. 4. It is concluded that filtration is possible and that secretion and resorption almost certainly occur in the formation of the urine. 5. A microthermopile is described. 6. Methods are described for measuring the hydrostatic pressure and the colloid osmotic pressures of the body fluids in small animals.

Effect of plasma osmolality on steady-state fluid shifts in perfused cat skeletal muscle

1993 ◽  
Vol 265 (6) ◽  
pp. R1318-R1323 ◽  
Author(s):  
M. T. Hamilton ◽  
D. S. Ward ◽  
P. D. Watson
Keyword(s):  
Steady State ◽  
Osmotic Pressure ◽  
Plasma Volume ◽  
Extracellular Volume ◽  
Plasma Osmolality ◽  
Apparent Volume ◽  
Colloid Osmotic Pressure ◽  
Blue Dye ◽  
Tissue Water ◽  
Wide Range

Fluid redistribution in isolated perfused cat calf muscle caused by rapid increases in plasma osmolality was studied using NaCl or sucrose. Extracellular tracers (51Cr-labeled EDTA or [3H]mannitol) were added to the perfusate 90 min before solutes were added, and samples were taken from plasma immediately before osmolality was increased and 17, 40, and 65 min later. Interstitial fluid volume (IFV) was calculated as extracellular volume (ECV) minus plasma volume (Evans blue dye). Total tissue water changes (delta TTW) were measured by continuous recording of tissue weight. Change in intracellular volume (delta ICV) was obtained from delta TTW--delta IFV. TTW, IFV, ICV, and plasma osmolality were in steady state after 17 min. Changes in hydrostatic and colloid osmotic pressure were insignificant in comparison with small-molecule osmotic pressure changes. The apparent volume of TTW participating in the fluid shift averaged 65 +/- 1 ml/100 g (SE) over a wide range of osmolality increases. In contrast to the large changes in TTW, IFV was not altered by osmolality. Thus decreases in TTW were similar to cell dehydration. Hence, increases in plasma volume induced by hypertonic fluids may come entirely at the expense of cell volume, not interstitial volume.

Edema in Spawning Salmon

1975 ◽  
Vol 32 (12) ◽  
pp. 2538-2541 ◽  
Author(s):  
Alan R. Hargens ◽  
M. Perez
Keyword(s):  
Osmotic Pressure ◽  
Fresh Water ◽  
Fluid Pressure ◽  
Colloid Osmotic Pressure ◽  
Spawning Migration ◽  
Degenerative Changes ◽  
Wick Technique ◽  
Total Body

Salmon develop edema during their spawning migration from the sea to fresh water. As measured by the wick technique, fluid pressure in both subcutaneous and peritoneal compartments rises from negative values at sea to positive values in rivers. Concomitantly, blood colloid osmotic pressure falls during the spawning migration. Some of the degenerative changes leading to the death of postspawning salmon probably result from the total-body edema herein described.

The Mechanism of Urine Formation in Invertebrates

1937 ◽  
Vol 14 (1) ◽  
pp. 20-34 ◽  
Author(s):  
L. E. R. PICKEN
Keyword(s):  
Sodium Chloride ◽  
Hydrostatic Pressure ◽  
Osmotic Pressure ◽  
Vapour Pressure ◽  
Average Rate ◽  
Colloid Osmotic Pressure ◽  
Pericardial Fluid ◽  
Anodonta Cygnea ◽  
Cent Sodium ◽  
Urine Formation

1. In Anodonta cygnea: (a) The blood has a vapour pressure equivalent to that of a solution of ca. 0.10 per cent sodium chloride. (b) The pericardial fluid is isotonic with the blood. (c) The urine has a vapour pressure equivalent to that of a solution of ca. 0.06 per cent sodium chloride. (d) The hydrostatic pressure of the blood is ca. 6 cm. of water. (e) The calculated colloid osmotic pressure is ca. 3.8 mm. of water. (f) The average rate of filtration of fluid into the pericardium is ca. 250 c.c. in 24 hours. (g) The salt uptake from ingested phytoplankton is estimated as equivalent to 0.012. g. sodium chloride in 24 hours. (h) The loss of osmotically active substance in the urine is estimated as equivalent to 0.15 g. sodium chloride in 24 hours. 2. In Limnaea peregra the vapour pressure of the blood is equivalent to that of a solution of ca. 0.43 per cent sodium chloride. The pericardial fluid is isotonic with the blood, and the urine has a concentration equivalent to ca. 0.30 per cent sodium chloride. 3. In Limnaea stagnalis the hydrostatic pressure of the blood is ca. 8 cm. of water. The colloid osmotic pressure of the blood is ca. 2.5 cm. of water (calculated); that of the pericardial fluid is ca. 0.7 cm. of water.

Evaluation of the Starling Fluid Flux Equation

Physiology ◽  
1987 ◽  
Vol 2 (2) ◽  
pp. 48-52 ◽  
Author(s):  
AE Taylor ◽  
MI Townsley
Keyword(s):  
Osmotic Pressure ◽  
Pressure Difference ◽  
Fluid Pressure ◽  
Colloid Osmotic Pressure ◽  
Lymph Flow ◽  
Tissue Fluid ◽  
Fluid Flux ◽  
Dynamic Factors ◽  
Osmotic Pressure Difference ◽  
Absorption Theory

It is commonly thought that fluid is filtered in the arterial and is absorbed in the venous end of the capillary, cuased by the considerable hydrostatic pressure difference between the arterial and the venous end, while the transcapillary colloid osmotic pressure difference remains nearly constant. We now know that extravascular forces, i.e., tissue fluid pressure, tissue colloid osmotic pressure, and lymph flow, are dynamic factors that change to oppose transcapillary fluid movement. Therefore, the filtration-absorption theory will apply only transiently until the tissue forces readjust.

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