Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1993 Jun;465:539–559. doi: 10.1113/jphysiol.1993.sp019692

Effect of extravascular plasma protein on pressure-flow relations across synovium in anaesthetized rabbits.

J N McDonald 1, J R Levick 1
PMCID: PMC1175445  PMID: 8229849

Abstract

1. The effect of extravascular plasma protein on fluid flux through interstitial matrix was investigated in vivo by studying the pressure-flow relation across synovium during intra-articular infusions of protein solutions (usually bovine serum albumin). Synovium is a sheet of non-epithelial cells separated by interstitium-filled gaps, beneath which are fenestrated capillaries: synovium regulates synovial fluid volume and composition. 2. Albumin solutions (10-150 g l-1) of measured oncotic pressure and viscosity were infused at known pressure into the synovial cavity of knees of anaesthetized rabbits. Flow across the synovial lining in the steady state (absorption rate Qs) was recorded at a series of joint pressures (Pj) to define the pressure-flow relation. Krebs solution was infused into the opposite knee as a control (26 animals). 3. Infusion of a low albumin concentration (10 g l-1, bovine or rabbit) or diluted rabbit serum revealed no specific effect of plasma protein on interstitial matrix permeability (cf. specific protein effect on capillary glycocalyx permeability). Physiological (22.5 g l-1) and higher concentrations reduced trans-synovial absorption rate. The slope of the pressure-flow relation was reduced and the pressure intercept displaced to the right (i.e. Pj at zero flow was raised). 4. Slope dQs/dPj correlated negatively with intra-articular viscosity (P = 0.001-0.04), in keeping with viscous interstitial flow. The reduction in normalized slope, however, did not equal the reduction in fluidity (1/viscosity) quantitatively. It is proposed that apparent fluidity within the interstitial matrix is higher than in the bulk phase due to steric exclusion of albumin (radius 3.55 nm) by the interstitial glycosaminoglycans. The latter form spaces of estimated mean hydraulic radius 14-18 nm in synovium. 5. The joint-pressure intercept at zero net trans-synovial flow was displaced 0.015 cmH2O per cmH2O intra-articular oncotic pressure (pi j; S.E.M. +/- 0.006). Thus large trans-synovial osmotic gradients were not maintained at physiological flow velocities. The 1.5% displacement of the Pj intercept by pi j was attributed principally to interstitial albumin exerting pericapillary oncotic pressure and enhancing net Starling filtration pressure. Indeed, net trans-synovial flow at low joint pressure sometimes reversed from absorption to filtration into the joint cavity at high intra-articular oncotic pressures. 6. The displacement of the trans-synovial flow intercept per unit change in intra-articular oncotic pressure, (dQs/d pi j)Pj = 0, was 18 +/- 3 nl min-1 cmH2O-1.(ABSTRACT TRUNCATED AT 400 WORDS)

Full text

PDF
539

Images in this article

553Fig. 7
on p.553

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Bassett J. E., Simkin P. A., Jacobs C., Roux E. Avoidance of endotoxin-induced inflammation during studies of albumin clearance from caprine joints. Exp Physiol. 1992 Nov;77(6):839–848. doi: 10.1113/expphysiol.1992.sp003650. [DOI] [PubMed] [Google Scholar]
  2. Knight A. D., Levick J. R. Effect of fluid pressure on the hydraulic conductance of interstitium and fenestrated endothelium in the rabbit knee. J Physiol. 1985 Mar;360:311–332. doi: 10.1113/jphysiol.1985.sp015619. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Knight A. D., Levick J. R., McDonald J. N. Relation between trans-synovial flow and plasma osmotic pressure, with an estimation of the albumin reflection coefficient in the rabbit knee. Q J Exp Physiol. 1988 Jan;73(1):47–65. doi: 10.1113/expphysiol.1988.sp003122. [DOI] [PubMed] [Google Scholar]
  4. Knight A. D., Levick J. R. Pressure-volume relationships above and below atmospheric pressure in the synovial cavity of the rabbit knee. J Physiol. 1982 Jul;328:403–420. doi: 10.1113/jphysiol.1982.sp014273. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Knox P., Levick J. R., McDonald J. N. Synovial fluid--its mass, macromolecular content and pressure in major limb joints of the rabbit. Q J Exp Physiol. 1988 Jan;73(1):33–45. doi: 10.1113/expphysiol.1988.sp003121. [DOI] [PubMed] [Google Scholar]
  6. Levick J. R. A two-dimensional morphometry-based model of interstitial and transcapillary flow in rabbit synovium. Exp Physiol. 1991 Nov;76(6):905–921. doi: 10.1113/expphysiol.1991.sp003553. [DOI] [PubMed] [Google Scholar]
  7. Levick J. R., Knight A. D. Interaction of plasma colloid osmotic pressure and joint fluid pressure across the endothelium-synovium layer: significance of extravascular resistance. Microvasc Res. 1988 Jan;35(1):109–121. doi: 10.1016/0026-2862(88)90054-4. [DOI] [PubMed] [Google Scholar]
  8. Levick J. R., McDonald J. N. Ultrastructure of transport pathways in stressed synovium of the knee in anaesthetized rabbits. J Physiol. 1989 Dec;419:493–508. doi: 10.1113/jphysiol.1989.sp017882. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Levick J. R., Michel C. C. The effect of bovine albumin on the permeability of frog mesenteric capillaries. Q J Exp Physiol Cogn Med Sci. 1973 Jan;58(1):87–97. doi: 10.1113/expphysiol.1973.sp002194. [DOI] [PubMed] [Google Scholar]
  10. Levick J. R. The influence of hydrostatic pressure on trans-synovial fluid movement and on capsular expansion in the rabbit knee. J Physiol. 1979 Apr;289:69–82. doi: 10.1113/jphysiol.1979.sp012725. [DOI] [PMC free article] [PubMed] [Google Scholar]
  11. McDonald J. N., Levick J. R. Evidence for simultaneous bidirectional fluid flux across synovial lining in knee joints of anaesthetized rabbits. Exp Physiol. 1992 May;77(3):513–515. doi: 10.1113/expphysiol.1992.sp003613. [DOI] [PubMed] [Google Scholar]
  12. Mehl J. W., Oncley J. L., Simha R. VISCOSITY AND THE SHAPE OF PROTEIN MOLECULES. Science. 1940 Aug 9;92(2380):132–133. doi: 10.1126/science.92.2380.132. [DOI] [PubMed] [Google Scholar]
  13. Michel C. C., Phillips M. E., Turner M. R. The effects of native and modified bovine serum albumin on the permeability of frog mesenteric capillaries. J Physiol. 1985 Mar;360:333–346. doi: 10.1113/jphysiol.1985.sp015620. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. PAPPENHEIMER J. R. Passage of molecules through capillary wals. Physiol Rev. 1953 Jul;33(3):387–423. doi: 10.1152/physrev.1953.33.3.387. [DOI] [PubMed] [Google Scholar]
  15. Palmer D. G., Myers D. B. Some observations of joint effusions. Arthritis Rheum. 1968 Dec;11(6):745–755. doi: 10.1002/art.1780110604. [DOI] [PubMed] [Google Scholar]
  16. Pedley T. J., Fischbarg J. The development of osmotic flow through an unstirred layer. J Theor Biol. 1978 Feb 20;70(4):427–447. doi: 10.1016/0022-5193(78)90251-5. [DOI] [PubMed] [Google Scholar]
  17. RENKIN E. M. Filtration, diffusion, and molecular sieving through porous cellulose membranes. J Gen Physiol. 1954 Nov 20;38(2):225–243. [PMC free article] [PubMed] [Google Scholar]
  18. Simkin P. A., Benedict R. S. Iodide and albumin kinetics in normal canine wrists and knees. Arthritis Rheum. 1990 Jan;33(1):73–79. doi: 10.1002/art.1780330109. [DOI] [PubMed] [Google Scholar]
  19. Stromberg D. D., Wiederhielm C. A. Effects of oncotic gradients and enzymes on negative pressures in implanted capsules. Am J Physiol. 1970 Oct;219(4):928–932. doi: 10.1152/ajplegacy.1970.219.4.928. [DOI] [PubMed] [Google Scholar]
  20. Tarbell J. M., Lever M. J., Caro C. G. The effect of varying albumin concentration of the hydraulic conductivity of the rabbit common carotid artery. Microvasc Res. 1988 Mar;35(2):204–220. doi: 10.1016/0026-2862(88)90063-5. [DOI] [PubMed] [Google Scholar]
  21. Taylor D. G., Bert J. L., Bowen B. D. A mathematical model of interstitial transport. I. Theory. Microvasc Res. 1990 May;39(3):253–278. doi: 10.1016/0026-2862(90)90042-p. [DOI] [PubMed] [Google Scholar]
  22. Tedgui A., Lever M. J. The interaction of convection and diffusion in the transport of 131I-albumin within the media of the rabbit thoracic aorta. Circ Res. 1985 Dec;57(6):856–863. doi: 10.1161/01.res.57.6.856. [DOI] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES