Biophysical Journal 69: 1429-1439 (1995)
© 1995 the Biophysical Society

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Price, F M Articles by Levick, J R Search for Related Content PubMed PubMed Citation Articles by Price, F M Articles by Levick, J R

Radial organization of interstitial exchange pathway and influence of collagen in synovium.

Department of Physiology, St. George's Hospital Medical School, London, England.

ABSTRACT

The synovial intercellular space is the path by which water, nutrients, cytokines, and macromolecules enter and leave the joint cavity. In this study two structural factors influencing synovial permeability were quantified by morphometry (Delesse's principle) of synovial electronmicrographs (rabbit knee), namely interstitial volume fraction Vv.1 and the fraction of the interstitium obstructed by collagen fibrils. Mean Vv.1 across the full thickness was 0.66 +/- 0.03 SEM (n = 11); but Vv.1 actually varied systematically with depth normal to the surface, increasing nonlinearly from 0.40 +/- 0.04 (n = 5 joints) near the free surface to 0.92 +/- 0.02 near the subsynovial interface. Tending to offset this increase in transport space, however, the space "blocked" by collagen fibrils also increased nonlinearly with depth. Bundles of collagen fibrils occupied 13.6 +/- 2.4% of interstitial volume close to the free surface but 49 +/- 4.8% near the subsynovial surface (full-thickness average, 40.5 +/- 3.5%), with fibrils accounting for 48.6-57.1% of the bundle space. Because of the two counteracting compositional gradients, the space available for fibril-excluded transport (hydraulic flow and macromolecular diffusion) was relatively constant > 4 microns below the surface but constricted at the synovium-cavity interface. The space available to extracellular polymers was only 51-53% of tissue volume, raising their effective concentration and hence the lining's resistance to flow and ability to confine the synovial fluid.

This article has been cited by other articles:

				K. R. Ingram, A. K. T. Wann, C. K. Angel, P. J. Coleman, and J. R. Levick Cyclic movement stimulates hyaluronan secretion into the synovial cavity of rabbit joints J. Physiol., March 15, 2008; 586(6): 1715 - 1729. [Abstract] [Full Text] [PDF]

				S. Sabaratnam, P. J. Coleman, R. M. Mason, and J. R. Levick Interstitial matrix proteins determine hyaluronan reflection and fluid retention in rabbit joints: effect of protease J. Physiol., January 1, 2007; 578(1): 291 - 299. [Abstract] [Full Text] [PDF]