The transport of particles across the walls of small blood vessels

doi:10.1098/rspb.1962.0025

The transport of particles across the walls of small blood vessels

Proceedings of the Royal Society of London Series B Biological Sciences ◽

10.1098/rspb.1962.0025 ◽

1962 ◽

Vol 156 (962) ◽

pp. 14-19 ◽

Cited By ~ 49

Keyword(s):

Iron Oxide ◽

Blood Vessels ◽

Rat Heart ◽

Colloidal Particles ◽

Perivascular Spaces ◽

Thorium Dioxide ◽

Perfused Rat Heart

Colloidal particles of thorium dioxide and saccharated iron oxide and molecules of ferritin enter the vesicles of the endothelium of the perfused rat heart. The first two substances have been shown to pass within the vesicles through the cells of the endothelium into the perivascular spaces.

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STUDIES ON THE CORNEA

The Journal of Cell Biology ◽

10.1083/jcb.12.3.457 ◽

1962 ◽

Vol 12 (3) ◽

pp. 457-479 ◽

Cited By ~ 103

Author(s):

Gordon I. Kaye ◽

George D. Pappas

Keyword(s):

Iron Oxide ◽

Anterior Chamber ◽

Aqueous Humor ◽

Colloidal Particles ◽

Corneal Stroma ◽

Thorium Dioxide ◽

Large Molecules ◽

To Receive ◽

Magnification Level

Physiological studies have demonstrated that ions, as well as large molecules such as hemoglobin or fluorescein, can diffuse across and within the cornea. Most of the substrates for corneal metabolism are obtained from aqueous humor filling the anterior chamber. In order to receive its nutrients and in order to maintain its normal conditions of hydration, the avascular cornea must transport relatively large amounts of solute and solvent across the cellular layers which cover this structure. It has been suggested in the past that there may be a morphological basis for the transport of large amounts of solvents and solutes by cells by the mechanism of pinocytosis. The use of electron-opaque markers to study fluid movements at the electron microscope magnification level was described by Wissig (29). The present study describes the fine structure of the normal rabbit cornea and the pathways of transport of colloidal particles by the cornea in vivo. Rabbit corneas were exposed in vivo to suspensions of saccharated iron oxide, thorium dioxide, or ferritin by injection of the material into the anterior chamber. In other experiments thorium dioxide or saccharated iron oxide was injected into the corneal stroma, producing a small bleb. Particles presented at the aqueous humor surface of the rabbit corneal endothelium are first attached to the cell surface and then pinocytosed. It appears that the particles are carried around the terminal bar by an intracellular pathway involving the pinocytosis of the particles and their subsequent transport in vesicles to the lateral cell margin basal to the terminal bar. Particles introduced at the basal surface of the endothelium (via blebs in the corneal stroma) are apparently carried through the endothelial cells in membrane-bounded vesicles without appearing in the intercellular space. There appears to be free diffusion of these particles through Descemet's membrane and the corneal stroma. The stromal cells take up large quantities of the particles when blebs are injected into the stroma.

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Ultrastructure of Lymphatic Capillaries in the Transport of Colloidal Particles

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100060945 ◽

1967 ◽

Vol 25 ◽

pp. 186-187

Author(s):

L. V. Leak ◽

J. F. Burke

Keyword(s):

Connective Tissue ◽

Colloidal Particles ◽

Ultrastructural Level ◽

Vital Role ◽

Time Intervals ◽

Thorium Dioxide ◽

Lymphatic Capillary ◽

Tissue Area ◽

Rapid Removal ◽

Tissue Fluids

The vital role played by the lymphatic capillaries in the transfer of tissue fluids and particulate materials from the connective tissue area can be demonstrated by the rapid removal of injected vital dyes into the tissue areas. In order to ascertain the mechanisms involved in the transfer of substances from the connective tissue area at the ultrastructural level, we have injected colloidal particles of varying sizes which range from 80 A up to 900-mμ. These colloidal particles (colloidal ferritin 80-100A, thorium dioxide 100-200 A, biological carbon 200-300 and latex spheres 900-mμ) are injected directly into the interstitial spaces of the connective tissue with glass micro-needles mounted in a modified Chambers micromanipulator. The progress of the particles from the interstitial space into the lymphatic capillary lumen is followed by observing tissues from animals (skin of the guinea pig ear) that were injected at various time intervals ranging from 5 minutes up to 6 months.

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