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F P Chinard

Publications and source records attributed to F P Chinard.

At least 19 recordsLinked to original sources
PubMed1992

Quantitative assessment of epithelial lining fluid in the lung.

Current techniques for the measurement lung epithelial fluid (ELF) volume depend on the dilution by a known volume of wash fluid (bronchoalveolar lavage) of a resident solute, such as urea, in the ELF or of a foreign solute introduced at known concentration in the lavage fluid. Knowledge of the ELF volume allows calculation of solute ELF concentrations. Urea concentration in ELF is assumed to be the same as in plasma. Although epithelial permeability to urea is low, entry of urea from tissues to lavage fluid occurs during the procedure and may lead to erroneous estimates of ELF volume as may loss of foreign solutes. Ideally, the extent of urea entry or of foreign solute loss should be estimated in each lavage. Other cautions are 1) equal osmolality of wash fluid and plasma, 2) minimizing residence time of wash fluid, 3) minimizing wash fluid-to-ELF volume ratio, and 4) adequate analytic procedures.

Body Fluids↗
PubMed1990

Endothelial and epithelial permeabilities to antipyrine in rat and dog lungs.

Temperature effects on the permeabilities of the structured endothelium and epithelium to antipyrine (AP) have been determined with the indicator dilution technique in isolated rat and dog lungs perfused between 38 and 8 degrees C. Permeability coefficients of the endothelium to AP [Pendo(AP)] from the Crone equation are smaller than values for isolated endothelial cells but close to the permeability coefficient of the interstitial epithelial plasmalemma [Pepi(AP)] obtained from physical and mathematical models. In these, tracer water is flow limited at the endothelium and the epithelium at all temperatures; AP is flow limited at the endothelium at T greater than 20 degrees C but barrier limited at the endothelium for T less than 20 degrees C and at the epithelium at all temperatures. At T less than 20 degrees C, log Pendo(AP) decreases regularly with 1/T, with a slope close to that found in cultured bovine pulmonary artery endothelial cells. At 15 degrees C, Pendo(AP) for the endothelial plasmalemma in situ is 30 X 10(-5) cm/s and is 56 X 10(-5) cm/s for the isolated cells in support of transcellular rather than paracellular passage. At T greater than 20 degrees C, log Pepi(AP) in situ decreases slightly with 1/T, with a discontinuity at T = 20 degrees C, and for T less than 20 degrees C, decreases with 1/T with a slope close to that of Pendo(AP). At 15 degrees C, Pepi(AP) is 2.8 X 10(-5) cm/s. The discontinuity may represent a change in the physical state of lipids in the interstitial plasmalemma of the epithelial cells.

Animals↗
PubMed1988

The osmotic permeability of isolated calf pulmonary artery endothelial cells.

Osmotic permeability coefficients, PF, for water in isolated calf pulmonary artery endothelial cells determined over the temperature range 41 to 20 degrees C are 311.10(-5) cm.s-1 at 37 degrees C and 159.10(-5) cm.s-1 at 20 degrees C. The value at 37 degrees C is close to that reported earlier for the diffusional permeability coefficient, PD. The PF/PD ratio is 1.0 at 37 degrees C. The PF values are within the range of values extrapolated for filtration permeability in pulmonary endothelium. The temperature dependence expressed as the activation energy is 7.2 kcal.mol-1. The product of hydraulic conductivity, Lp (or PF) and of viscosity changes in water is not constant from 37 to 20 degrees C. These results can be interpreted to indicate a similar pathway for water whether under diffusional or osmotic gradients.

Animals↗
PubMed1988

The influence of circulatory overload on extraalveolar microvessel endothelium of dog lung in vivo.

In an earlier study from this laboratory, morphometric evaluations of the alveolar capillary endothelium of the lungs of intact dogs were recorded after periods of sustained increases of pulmonary microvascular pressures (D. O. DeFouw, W. O. Cua, and F. P. Chinard, 1983, Microvasc. Res. 25, 56-67). In the present study ultrastructural characteristics of the extraalveolar microvessel endothelium of these dog lungs were evaluated. Small (25- to 50-microns luminal diameter) nonmuscular vessels, which adjoin the alveolar capillaries, and larger (51-200 microns) partially muscular and muscular microvessels were assessed. After increased microvascular filtration, to be expected from the increased hydrostatic pressures, fluid accumulation was found only in the connective tissue sleeves of the larger microvessels. The endothelium of these partially muscular and muscular vessels was markedly affected by fluid distension of the periendothelial interstitium. The endothelial response included the appearance of basal (abluminal) surface invaginations, de novo plasmalemmal vesicle formation, and increased numbers of cytoplasmic vacuoles. The small nonmuscular microvessels lacked both the fluid cuffs and the alterations of endothelial ultrastructure. This latter observation is consistent with the previous report from this laboratory that indicated an absence of both alveolar septal edema and increased capillary endothelial vesicle densities in these lungs (DeFouw et al., 1983). Thus, it seems likely that the conformational changes of the endothelium of the larger microvessels were related to the formation of the periendothelial fluid cuffs. The mechanisms responsible for this endothelial response have not been determined but can be explained on the basis of the testable hypothesis that they are secondary to an increase of tissue pressure associated with accumulation of tissue fluid. These changes may thus represent a secondary structural adaptation to the increased tissue pressures and may serve as a potential vesicular-vacuolar pathway across the endothelium.

Animals↗
PubMed1988

Water permeability of isolated endothelial cells at different temperatures.

The endothelial cells provide a potential pathway for water movement across the endothelium. The endothelial cell permeability to water can, therefore, be a factor in regulation of the rate of water movement out of the vasculature. Endothelial cells are isolated from calf pulmonary artery and cultured. The cells are removed from culture, and the diffusional water permeability is determined with the linear diffusion technique. The mean membrane permeability coefficients (PDS) determined at 20, 30, 37, and 41 degrees C are 160, 273, 304, and 387 x 10(-5) cm/s, respectively. The temperature dependence of PD is calculated with the Arrhenius equation to be 7.2 kcal/mol. If these values of PD are compared with values we have reported for the osmotic permeability coefficient (PF), the PF/PD is about one at each temperature. The values of PD in the isolated endothelial cells are compared with PD for endothelial cells estimated from whole organ studies and are similar to recently reported values.

Animals↗
PubMed1987

Endothelial extraction of tracer water varies with extravascular water in dog lungs.

In multiple indicator-dilution experiments, transvascular passage of a permeating indicator is conventionally derived from the up-slope separation of the curve of the permeating indicator from that of a vascular reference and is expressed as the extraction (Ec). Extraction may be limited by the barrier (barrier-limited distribution). It may be limited by the volume of distribution accessible to it; in the time domain of an indicator-dilution experiment, the passage to and distribution in the extravascular volume are rapid relative to the velocity of blood in the exchange vessels. We examine here the relations of the extraction of tracer water as tritium oxide (THO) [Ec(THO)] and of the extraction of tracer sodium as 22Na [Ec(22Na)] to extravascular lung water, delta V wev, by adding isotonic fluid to the gas phase of the lungs. The net convective transvascular passage of water is negligible relative to the transendothelial molecular exchange. In 10 experiments in vivo and in 10 experiments in isolated perfused lungs, Ec(THO) increases as delta V wev increases. Ec(22Na) and the permeability-surface area product (PS) for 22Na do not change as delta V wev increases. We conclude that the extraction of THO is determined mainly by the volume accessible to it (flow- or volume-limited distribution) and that the extraction of 22Na is determined mainly by the resistance of the endothelium (barrier-limited distribution). A diffusion limitation in the added alveolar fluid rather than a barrier limitation at the endothelium may moderate Ec(THO).

Animals↗
PubMed1986

Endothelial cell permeability to water.

We have calculated diffusional permeability coefficients for tracer water and for [14C]antipyrine in endothelial cells. With these values and those from studies in whole lungs we set a range for diffusional water permeability coefficients of the intact endothelium.

Animals↗
PubMed1986

Water permeability of alveolar macrophages.

The hydraulic conductivity coefficient (Lp) of alveolar macrophages, recovered by lavage from dog lungs, was determined by following volume changes induced by changes of nonpermeating solute concentrations of suspending fluid as a function of time at 20 degrees C. The volume changes were monitored as changes in absorbance of the suspended cells at 600 nm. Cell surface area was calculated from cell volume and diameter. Linear relationships between cell volume and solution osmolality changes were found over the range of 320-520 mosmol/kg; beyond these ranges the macrophages did not respond with swelling or shrinking. Lp and the filtration coefficient (Pf) were calculated from the total volume change over time. At 20 degrees C these were, respectively, 15.7 X 10(-10) cm X cmH2O-1 X s-1 and 217 X 10(-5) cm/s. Comparison of Pf and the diffusional permeability coefficient (Pd) for water of 70 X 10(-5) cm/s, yields a Pf-to-Pd ratio of 3.1. The hypothesis of water passage through aqueous membrane pores is compatible with these data. However, diffusion of water in the glycocalyx of the pericellular domain could be restricted. Pd would then be underestimated, and a falsely high ratio would be calculated. We have no evidence to support this possibility.

Animals↗
PubMed1986

Terminology for mass transport and exchange.

Virtually all fields of physiological research now encompass various aspects of solute transport by convection, diffusion, and permeation across membranes. Accordingly, this set of terms, symbols, definitions, and units is proposed as a means of clear communication among workers in the physiological, engineering, and physical sciences. The goal is to provide a setting for quantitative descriptions of physiological transport phenomena.

Animals↗
PubMed1986

Endothelial extraction of tracer water is independent of temperature in dog lungs.

Diffusion and viscosity-dependent flow rates generally decrease with decrease of temperature in biological systems. We have examined the extraction (Ec) of tracer water in isolated dog lungs perfused near 37 degrees C and near 15 degrees C with multiple-indicator dilution experiments. If Ec were barrier limited, Ec should be less at lower temperatures. Two runs at 37 degrees C were followed by two runs at 15 degrees C. Evans blue (T-1824) was used as vascular reference, and tritium oxide (THO) was used as water tracer. Values of Ec were based on the ratio of the areas under the two indicator curves from appearance time to time of peak of T-1824. Values for permeability-surface area (PS) products were calculated from the classical Crone relationship in 14 experiments with a total of 56 runs. Neither Ec nor PS decreased with temperature. Instead, modest but statistically significant increases were found. We conclude that the extraction of tracer water in these preparations is not barrier limited.

Animals↗
PubMed1985

Alveolar microvessels in isolated perfused dog lungs: structural and functional studies after production of moderate and severe hydrodynamic edema.

We have reported earlier that increased endothelial vesiculation follows the development of septal edema and alveolar flooding in isolated dog lung preparations. In this report, established ultrastructural morphometric analyses are coupled with data from physiologic and indicator-dilution studies to evaluate the stage of edema development at which de novo formation of alveolar microvessel plasmalemmal vesicles occurs. The interpretation that alveolar microvessel plasmalemmal vesicles increase prior to alveolar flooding, the final stage of edema formation, is consistent with the results reported here. Moderate pulmonary edema, characterized by substantial fluid cuffing around extra-alveolar arteries and veins and by fluid accumulation restricted to the thick sides of the alveolar septa, is associated with increased vesiculation in alveolar vessel endothelium. Further, a larger percentage of the vesicle population seen is directly attached to the endothelial luminal or abluminal surfaces. The functional significance of an increased population and an altered intracellular distribution of vesicles remains undetermined. The vesicles may provide a minor defense against excessive septal interstitial fluid accumulation, and subsequent alveolar flooding, by contributing to retrograde transport to the blood. Increased vesiculation, on the other hand, may represent an adaptive cellular response to interstitial fluid accumulation.

Animals↗
PubMed1984

Solute-excluded volumes near the Novikoff cell surface.

A differential centrifugation technique, in which all extracellular water except that intimately associated with the cell (pericellular domain) is removed, has been applied to isolated Novikoff hepatoma cells. The pericellular volumes accessible to albumin, inulin, raffinose, and sucrose were inversely related to the molecular weights of the test solutes. This phenomenon was not detectable in erythrocytes or in fat cells. Selective removal of cell surface components by enzymatic treatment produced proportional changes in the relative volumes of distribution accessible to the solutes. This discrimination in the volume accessible to each of the solutes is analogous to that obtained in gel chromatographic separation and represents, in effect, excluded volumes which are inversely related to solute size. This exclusion is associated with components of the Novikoff cell surface, including the surface coat and the microvilli that cover the Novikoff cell. These structures provide an additional level of discrimination for the Novikoff cell not seen in certain other cell types.

Animals↗
PubMed1983

Effects of sulfhydryl and other reagents on the diffusional permeability of dog erythrocytes to small solutes.

The effects of p-chloromercuriphenylsulfonic acid (PCMBS), 5,5'-dithiobis (2-nitrobenzoic acid) (DTNB), phloretin and thiourea on the diffusional permeability of dog erythrocytes to tritiated water and to small 14C-labeled lipophilic and hydrophilic solutes were measured at 37 degrees C by means of the linear diffusion technique. Permeability to 3HHO was significantly decreased by PCMBS but was not affected by the other reagents. The permeability to the small hydrophilic solutes acetamide and urea was decreased by phloretin and thiourea but only the permeability to acetamide was reduced to a statistically significant extent by PCMBS. The permeability to the lipophilic solutes methanol, ethanol and antipyrine was not affected by any of these agents. We interpret these results as an indication that the small lipophilic solutes probably move through lipid areas, that the small hydrophilic solutes probably move through protein associated areas in the erythrocyte membrane and that pathways for the small hydrophilic solutes are distinct from those for water. While the pathways for water may be associated with membrane protein they do not appear to be associated specifically with band 3 protein as has been suggested for human erythrocytes. Diffusional water movement through the dog erythrocyte occurs by two distinct pathways.

4-Chloromercuribenzenesulfonate↗
PubMed1983

Variations in cellular attenuation and vesicle numerical densities in capillary endothelium and type I epithelium of isolated, perfused dog lungs after acute severe edema formation.

Morphometric comparisons of nonedematous and edematous isolated, perfused dog lungs establish that there are significant differences between the degree of cellular attenuation and vesicle numerical densities in endothelial and type I epithelial cells of the alveolar septa after edema production. In nonedematous isolated lungs the extent of endothelial and epithelial attenuation was greater on the thin sides of the septa. In the edematous lungs, the differential of greater thin-side attenuation was maintained for the endothelium but not for the epithelium where the extent of attenuation in the septal thick segments was increased. Vesicle numerical densities were approximately doubled in the cells on both sides of the septa in the edematous lungs. The endothelial vesicle densities were greater in the septal thin segments than in the septal thick segments in both the nonedematous and the edematous isolated lungs. The epithelial vesicle densities, on the other hand, were similar on the thin and thick sides of the septa in the nonedematous and edematous lung preparations. Although the contribution of vesicles to cellular function in the alveolar septa remains uncertain, further evaluation of vesicular transport should include the possible variability of this function with the varying degrees of cellular attenuation on the two anatomically distinct sides of the septa.

Animals↗