Transcapillary fluid shifts in tissues of the head and neck during and after simulated microgravity

1991 ◽  
Vol 71 (6) ◽  
pp. 2469-2475 ◽  
Author(s):  
S. E. Parazynski ◽  
A. R. Hargens ◽  
B. Tucker ◽  
M. Aratow ◽  
J. Styf ◽  
...  
Keyword(s):  
Time Course ◽  
Interstitial Fluid ◽  
Baseline Period ◽  
Colloid Osmotic Pressure ◽  
Tissue Fluid ◽  
Fluid Filtration ◽  
Lower Lip ◽  
Facial Edema ◽  
Capillary Pressures ◽  
Male Subjects

To understand the mechanism, magnitude, and time course of facial puffiness that occurs in microgravity, seven male subjects were tilted 6 degrees head-down for 8 h, and all four Starling transcapillary pressures were directly measured before, during, and after tilt. Head-down tilt (HDT) caused facial edema and a significant elevation of microvascular pressures measured in the lower lip: capillary pressures increased from 27.7 +/- 1.5 mmHg (mean +/- SE) pre-HDT to 33.9 +/- 1.7 mmHg by the end of tilt. Subcutaneous and intramuscular interstitial fluid pressures in the neck also increased as a result of HDT, whereas interstitial fluid colloid osmotic pressures remained unchanged. Plasma colloid osmotic pressure dropped significantly by 4 h of HDT (21.5 +/- 1.5 mmHg pre-HDT to 18.2 +/- 1.9 mmHg), suggesting a transition from fluid filtration to absorption in capillary beds between the heart and feet during HDT. After 4 h of seated recovery from HDT, microvascular pressures in the lip (capillary and venule pressures) remained significantly elevated by 5–8 mmHg above baseline values. During HDT, urine output was 126.5 ml/h compared with 46.7 ml/h during the control baseline period. These results suggest that facial edema resulting from HDT is caused primarily by elevated capillary pressures and decreased plasma colloid osmotic pressures. The negativity of interstitial fluid pressures above heart level also has implications for maintenance of tissue fluid balance in upright posture.

Isolation of interstitial fluid from rat mammary tumors by a centrifugation method

2003 ◽  
Vol 284 (1) ◽  
pp. H416-H424 ◽  
Author(s):  
Helge Wiig ◽  
Knut Aukland ◽  
Olav Tenstad
Keyword(s):  
Interstitial Fluid ◽  
Tumor Tissue ◽  
Venous Blood ◽  
Lymphatic Drainage ◽  
Colloid Osmotic Pressure ◽  
Low Molecular Weight ◽  
Tissue Fluid ◽  
Arterial Plasma ◽  
Lower Ratio ◽  
Superficial Tumor

Access to interstitial fluid is of fundamental importance to understand tumor transcapillary fluid balance, including the distribution of probes and therapeutic agents. Tumors were induced by gavage of 9,10-dimethyl-1,2-benzanthracene to rats, and fluid was isolated after anesthesia by exposing tissue to consecutive centrifugations from 27 to 6,800 g. The observed51Cr-EDTA (extracellular tracer) tissue fluid-to-plasma ratio obtained from whole tumor or from superficial tumor tissue by centrifugation at 27–424 g was not significantly different from 1.0 (0.92–0.99), suggesting an extracellular origin only. However, fluid collected from excised central tumor parts had a significantly lower ratio (0.66–0.77) for all imposed G forces, suggesting dilution by fluid deriving from a space unavailable for51Cr-EDTA. The colloid osmotic pressure in tumor fluid was generally higher than in fluid isolated from the subcutis, attributable to less selective capillaries and impaired lymphatic drainage in tumors. HPLC analysis of tumor fluid showed that low-molecular-weight macromolecules not present in arterial plasma were present in tumor fluid obtained by centrifugation and in venous blood draining the tumor, most likely representing proteins derived from tumor cells. We conclude that low-speed centrifugation may be a simple and reliable method to isolate interstitial fluid from tumors.

Isolation of interstitial fluid in skin during volume expansion: evaluation of a method in pigs

2010 ◽  
Vol 299 (5) ◽  
pp. H1546-H1553 ◽  
Author(s):  
H. K. Brekke ◽  
E. Oveland ◽  
O. Kolmannskog ◽  
S. M. Hammersborg ◽  
H. Wiig ◽  
...  
Keyword(s):  
Volume Expansion ◽  
Interstitial Fluid ◽  
Pigment Epithelium ◽  
Experimental Studies ◽  
Colloid Osmotic Pressure ◽  
Size Exclusion ◽  
Fluid Filtration ◽  
Fatty Acid Binding ◽  
Specific Proteins ◽  
Centrifugation Method

The ability to isolate interstitial fluid (IF) from skin would make it possible to study the microcirculation and proteins in this environment both during normal and pathophysiological conditions. Traditional IF sampling using implanted wicks suffer from low volumes with risk of contamination by local inflammatory, intracellular, and vascular proteins. To sample larger volumes of true IF, a recently described tissue centrifugation method was compared with dry and wet wicks from porcine skin under normal conditions and following volume expansion. With all three methods, volume expansion caused a significant lowering of interstitial colloid osmotic pressure as expected, and the fluid was similar to plasma when compared using size-exclusion HPLC. The centrifugation method was superior with respect to isolating larger amounts of true IF for further studies. Mass spectrometry of IF sampled with centrifugation showed that most of the proteins reflected the major plasma proteins with some tissue-specific proteins like decorin, gelsolin, and orosomucoid-1. Lumican, pigment epithelium-derived factor, and fatty acid-binding protein 4 were only identified in IF after volume expansion, possibly reflecting a local response to increased fluid filtration. Tissue centrifugation to collect IF from skin should be applicable to both clinical and experimental studies on IF balance during different pathophysiological conditions and interventions.

Lowering of interstitial fluid pressure in rat submandibular gland: a novel mechanism in saliva secretion

2006 ◽  
Vol 290 (4) ◽  
pp. H1460-H1468 ◽  
Author(s):  
Ellen Berggreen ◽  
Helge Wiig
Keyword(s):  
Osmotic Pressure ◽  
Submandibular Gland ◽  
Interstitial Fluid ◽  
Fluid Transport ◽  
Fluid Pressure ◽  
Myoepithelial Cells ◽  
Colloid Osmotic Pressure ◽  
Interstitial Fluid Pressure ◽  
High Rate ◽  
Fluid Filtration

The submandibular gland transports fluid at a high rate through the interstitial space during salivation, but the exact level of all forces governing transcapillary fluid transport has not been established. In this study, our aim was to measure the relation between interstitial fluid volume (Vi) and interstitial fluid pressure (Pif) in salivary glands during active secretion and after systemically induced passive changes in gland hydration. We tested whether interstitial fluid could be isolated by tissue centrifugation to enable measurement of interstitial fluid colloid osmotic pressure. During control conditions, Vi averaged 0.23 ml/g wet wt (SD 0.014), with a corresponding mean Pif measured with micropipettes of 3.0 mmHg (SD 1.3). After induction of secretion by pilocarpine, Pif dropped by 3.8 mmHg (SD 1.5) whereas Vi was unchanged. During dehydration and overhydration of up to 20% increase of Vi above control, a linear relation was found between volume and pressure, resulting in a compliance (ΔVi/ΔPif) of 0.012 ml·g wet wt−1·mmHg−1. Interstitial fluid was isolated, and interstitial fluid colloid osmotic pressure averaged 10.4 mmHg (SD 1.2), which is 64% of the corresponding level in plasma. We conclude that Pif drops during secretion and, thereby, increases the net transcapillary pressure gradient, a condition that favors fluid filtration and increases the amount of fluid available for secretion. The reduction in Pif is most likely induced by contraction of myoepithelial cells and suggests an active and new role for these cells in salivary secretion. The relatively low interstitial compliance of the organ will enhance the effect of the myoepithelial cells on Pif during reduced Vi.

Isolation of interstitial fluid from skeletal muscle and subcutis in mice using a wick method

2004 ◽  
Vol 287 (5) ◽  
pp. H2085-H2090 ◽  
Author(s):  
Carl Erik Markhus ◽  
Helge Wiig
Keyword(s):  
Skeletal Muscle ◽  
Plasma Proteins ◽  
Interstitial Fluid ◽  
Colloid Osmotic Pressure ◽  
Tissue Fluid ◽  
Protein Extravasation ◽  
Plasma Protein Extravasation ◽  
Wick Technique ◽  
Region Plasma ◽  
Gain Access

Until recent years, mice were sparsely used in physiological experiments, and therefore, data on the basic cardiovascular parameters of mice are lacking. Our aim was to gain access to interstitial fluid and thereby study transcapillary fluid dynamics in this species. Using a modified wick method, we were able to isolate interstitial fluid from subcutis and skeletal muscle in mice. Three-stranded, dry, nylon wicks were inserted post mortem in an attempt to avoid local inflammation and thus eliminate protein extravasation and wick contamination. Colloid osmotic pressure (COP) was measured with a colloid osmometer for submicroliter samples and averaged (means ± SE) 18.7 ± 0.4 in plasma, 9.1 ± 0.4 in subcutis, and 12.3 ± 0.5 mmHg in muscle. HPLC of plasma and wick fluid showed similar patterns except for some minor peaks eluting in the <40-kDa region. Plasma protein extravasation as determined by 125I-labeled human serum albumin showed that contamination of wick fluid by plasma proteins was negligible (<2%). Capillary hyperfiltration induced by intravenous infusion of saline (10% of body wt) was reflected in tissue fluid isolated by wicks as shown by the average postinfusion COP values of 14.5 ± 0.6, 6.8 ± 0.3, and 7.7 ± 0.4 mmHg in plasma, subcutis, and muscle, respectively. We conclude that the wick technique can be easily adapted for use in mice and may represent a reliable method to isolate interstitial fluid and study transcapillary fluid flux in this species.

Alveolar pressure and lung volume as determinants of net transvascular fluid filtration

1977 ◽  
Vol 42 (4) ◽  
pp. 476-482 ◽  
Author(s):  
G. Bo ◽  
A. Hauge ◽  
G. Nicolaysen
Keyword(s):  
Lung Volume ◽  
Continuous Monitoring ◽  
Interstitial Fluid ◽  
Positive Airway Pressure ◽  
Fluid Pressure ◽  
Alveolar Pressure ◽  
Experimental Conditions ◽  
Fluid Filtration ◽  
Pulmonary Arterial ◽  
Relative Change

We have investigated the influence of changes in alveolar pressure (PAlv) and in lung volume on the net transvascular fluid filtration rate (FFR). The preparation was isolated, perfused zone III rabbit lungs. In observation periods the outflow pressure was kept constant at a level generally causing net filtration. All pressures were measured relative to atmospheric. FFR was measured by continuous monitoring of preparation weight. Elevation of Palv at constant lung volume caused reversible reductions in FFR, also at constant capillary hydrostatic pressure (Pa-V less than 2 Torr). Increases in lung volume at constant PAlv caused reversible increases in FFR. When both PAlv and Ptp were increased a reduction in FFR was seen in the majority of cases. We conclude that at constant pulmonary arterial pressure, the size and the direction of the influence of positive airway pressure on FFR depend on the relative change in lung volume and in alveolar pressure per se. Under the present experimental conditions a rise in PAlv will be transmitted to interstitial fluid pressure and affect the transvascular fluid balance.

Fluid exchanges across the parietal peritoneal and pleural mesothelia

1993 ◽  
Vol 74 (4) ◽  
pp. 1779-1784 ◽  
Author(s):  
D. Negrini ◽  
M. del Fabbro ◽  
D. Venturoli
Keyword(s):  
Protein Concentration ◽  
Fluid Pressure ◽  
Colloid Osmotic Pressure ◽  
Small Samples ◽  
Tissue Fluid ◽  
Liquid Pressure ◽  
Null System ◽  
Net Pressure ◽  
Linear Regressions

In 31 anesthetized rabbits, after removal of superficial tissues, glass micropipettes filled with 0.5 M NaCl solution and connected to an electrohydraulic servo-null system were used to measure extraperitoneal interstitial fluid pressure (Pi,per) and peritoneal liquid pressure (Pliq,per) at various heights. Linear regressions relating pressure to recording height (H) were Pi,per = 1.07 – 0.27H and Pliq,per = 0.9 – 0.64H, respectively. Protein concentration (Cp;g/dl) and colloid osmotic pressure (II; cmH2O) of plasma and of peritoneal and pleural liquids were 5.48 +/- 0.38 and 24.61 +/- 3.23, 3.07 +/- 0.5 and 13.29 +/- 1.87, and 1.76 +/- 0.42 and 8.45 +/- 2, respectively. The equation relating II to Cp was II = 4.64Cp + 0.0027Cp2. Tissue fluid samples were collected with saline-soaked wicks implanted in vivo or dry wicks inserted postmortem in extraperitoneal and extrapleural interstitial spaces. After 60 and 15 min, respectively, wicks were withdrawn and centrifuged; wick fluid was analyzed in colloid osmometer for small samples. Average extraperitoneal and extrapleural II values were 14.2 +/- 2.49 and 11.94 +/- 1.52 cmH2O, corresponding to Cp of 3.07 and 2.57 g/dl, respectively. The average net pressure gradient, assuming reflection coefficient and hydraulic conductivity (Negrini et al. J. Appl. Physiol. 69: 625–630, 1990; 71: 2543–2547, 1991), was 1.18 and 0.98 cmH2O for parietal peritoneal and pleural mesothelia, respectively, favoring filtration from the extraserosal interstitia into the serosal cavities. Total parietal peritoneal filtration was 1.49 ml.kg-1.h-1, approximately 15-fold higher than that for pleural mesothelium.

Osmoregulation and interstitial fluid pressure changes in humans during water immersion

1981 ◽  
Vol 51 (3) ◽  
pp. 686-692 ◽  
Author(s):  
S. S. Khosla ◽  
A. B. DuBois
Keyword(s):  
Interstitial Fluid ◽  
Water Immersion ◽  
Plasma Concentrations ◽  
Fluid Pressure ◽  
Interstitial Fluid Pressure ◽  
Sodium Potassium ◽  
Maximum Decrease ◽  
Blood And Urine Samples ◽  
Pressure Changes ◽  
Male Subjects

The aim of the present study was to determine the magnitude and direction of the shift of body fluids during water immersion of humans to the neck. Five healthy male subjects were studied lying in air for 1.5 h, sitting in 34 degrees C water to the neck for 1 h, and again lying in air for 1.5 h in two sets of experiments. For the first set, vasopressin (0.75 IU, sc) was injected before immersion. Blood and urine samples were drawn every 30 min in air and every 20 min in water. Urinary sodium, potassium, and osmolal clearances were significantly increased during immersion. When the mean maximum change during immersion was calculated for five subjects hematocrit fell by 1.1 U, plasma concentrations of sodium by 3.9 meq/l, chloride by 3.5 meq/l, potassium by 0.2 meq/l, osmolality by 7.9 mosmol/kg H2O, and proteins by 0.25 g/100 ml, whereas total plasma CO2 content increased by 1.33 mmol/l, threonine by 11.6%, proline by 9.0%, methionine by 14.0%, and alanine by 29%. Plasma volume increased 6.1%, and red blood cell volume calculated from hematocrit and hemoglobin increased 3.5%. In the second set of immersion experiments, without vasopressin injection, interstitial fluid pressures were measured with a cotton wick in PE-50 tubing inserted subcutaneously. A mean interstitial fluid pressure of -0.5 cmH2O was observed when the subjects were lying in air. Interstitial fluid pressure had started to decrease by 20 min of immersion, with a maximum decrease during immersion averaging 2.10 cmH2O. We conclude that hyposmotic fluid is mobilized into the blood from interstitial and other extravascular spaces during immersion.

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.

Effect of duration of exercise on excess postexercise O2 consumption

1987 ◽  
Vol 62 (2) ◽  
pp. 485-490 ◽  
Author(s):  
R. Bahr ◽  
I. Ingnes ◽  
O. Vaage ◽  
O. M. Sejersted ◽  
E. A. Newsholme
Keyword(s):  
Rectal Temperature ◽  
Time Course ◽  
Control Experiment ◽  
Respiratory Exchange Ratio ◽  
Exercise Duration ◽  
Cycle Ergometer ◽  
O2 Consumption ◽  
Work Intensity ◽  
O2 Uptake ◽  
Male Subjects

This study was undertaken to determine the effect of exercise duration on the time course and magnitude of excess postexercise O2 consumption (EPOC). Six healthy male subjects exercised on separate days for 80, 40, and 20 min at 70% of maximal O2 consumption on a cycle ergometer. A control experiment without exercise was performed. O2 uptake, respiratory exchange ratio (R), and rectal temperature were monitored while the subjects rested in bed 24 h postexercise. An increase in O2 uptake lasting 12 h was observed for all exercise durations, but no increase was seen after 24 h. The magnitude of 12-h EPOC was proportional to exercise duration and equaled 14.4 +/- 1.2, 6.8 +/- 1.7, and 5.1 +/- 1.2% after 80, 40, and 20 min of exercise, respectively. On the average, 12-h EPOC equaled 15.2 +/- 2.0% of total exercise O2 consumption (EOC). There was no difference in EPOC:EOC for different exercise durations. A linear decrease with exercise duration was observed in R between 2 and 24 h postexercise. No change was observed in recovery rectal temperature. It is concluded that EPOC increases linearly with exercise duration at a work intensity of 70% of maximal O2 consumption.

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