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. 1981 Jun;315:127–142. doi: 10.1113/jphysiol.1981.sp013737

The role of vesicles in the transport of ferritin through frog endothelium.

G Clough, C C Michel
PMCID: PMC1249372  PMID: 6975816

Abstract

1. The transport of ferritin molecules by endothelial cell vesicles has been quantitatively investigated by electron microscopy. Single mesenteric capillaries of pithed frogs were perfused with solutions containing 6.7 g ferritin 100 ml.-1 for known periods before fixation in situ with osmium tetroxide. 2. Two series of experiments were carried out: in the first series the perfusate contained bovine serum albumin (1.0 g 100 ml.-1); in the second series the perfusate contained no protein other than the ferritin. To assess the molecular radius of ferritin in solution, the free diffusion coefficient of ferritin was measured in the presence and absence of albumin. 3. The free diffusion coefficient of ferritin in saline solution (110 m-mole 1.-1) was found to be 0.35 X 10(-6) cm2 sec-1 at 21 degrees C and was not affected by the presence of bovine serum albumin. This indicates that there is no significant binding of albumin to ferritin in solution and yields a value for the Stokes-Einstein radius of ferritin of 6.1 nm. 4. In all perfusion experiments the percentage of luminal vesicles containing ferritin exceeded the percentage of labelled cytoplasmic vesicles, which in turn exceeded the percentage of labelled abluminal vesicles. 5. Labelling of all vesicle populations was seen after perfusions lasting less than 1 sec. At this time luminal vesicles were more heavily labelled in the absence of albumin. 6. The labelling of luminal vesicles increased with lengthening perfusion times up to 30-40 sec, after which steady levels of labelling were achieved. The rate of rise in luminal labelling and the steady-state levels reached were both greater in the absence of albumin. By contrast cytoplasmic labelling increased above its initial value only after perfusions of longer than 10 sec. 7. In the steady state, labelled cytoplasmic vesicles contained, on average, fewer ferritin molecules than labelled luminal vesicles. This finding is inconsistent with translocation of labelled luminal vesicles across the cell. 8. It is suggested that the early constant labelling of cytoplasmic and abluminal vesicles is consistent with the existence of vesicular channels. Later cytoplasmic labelling may result from the transient fusion of cytoplasmic vesicles with labelled luminal vesicles for periods long enough to allow mixing of vesicular contents. Albumin may affect vesicular transport by its interaction with the endothelial glycocalyx.

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Selected References

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

  1. Bruns R. R., Palade G. E. Studies on blood capillaries. II. Transport of ferritin molecules across the wall of muscle capillaries. J Cell Biol. 1968 May;37(2):277–299. doi: 10.1083/jcb.37.2.277. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bundgaard M., Frøkjaer-Jensen J., Crone C. Endothelial plasmalemmal vesicles as elements in a system of branching invaginations from the cell surface. Proc Natl Acad Sci U S A. 1979 Dec;76(12):6439–6442. doi: 10.1073/pnas.76.12.6439. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Clough G., Michel C. C. The effect of albumin on the labelling of endothelial cell vesicles with ferritin in the frog [proceedings]. J Physiol. 1979 Apr;289:72P–73P. [PubMed] [Google Scholar]
  4. Clough G., Michel C. C. The sequence of labelling of endothelial cell vesicles with ferritin in the frog [proceedings]. J Physiol. 1979 Jul;292:61P–662. [PubMed] [Google Scholar]
  5. Green H. S., Casley-Smith J. R. Calculations on the passage of small vesicles across endothelial cells by Brownian motion. J Theor Biol. 1972 Apr;35(1):103–111. doi: 10.1016/0022-5193(72)90195-6. [DOI] [PubMed] [Google Scholar]
  6. Hoare R. J., Harrison P. M., Hoy T. G. Structure of horse-spleen apoferritin at 6 angstom resolution. Nature. 1975 Jun 19;255(5510):653–654. doi: 10.1038/255653a0. [DOI] [PubMed] [Google Scholar]
  7. Jennings M. A., Florey L. An investigation of some properties of endothelium related to capillary permeability. Proc R Soc Lond B Biol Sci. 1967 Jan 31;167(1006):39–63. doi: 10.1098/rspb.1967.0012. [DOI] [PubMed] [Google Scholar]
  8. Johansson B. R. Permeability of muscle capillaries to interstitially microinjected ferritin. Microvasc Res. 1978 Nov;16(3):362–368. doi: 10.1016/0026-2862(78)90069-9. [DOI] [PubMed] [Google Scholar]
  9. Karnovsky M. J. The ultrastructural basis of capillary permeability studied with peroxidase as a tracer. J Cell Biol. 1967 Oct;35(1):213–236. doi: 10.1083/jcb.35.1.213. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. 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]
  11. Levick J. R., Michel C. C. The permeability of individually perfused frog mesenteric capillaries to T1824 and T1824-albumin as evidence for a large pore system. Q J Exp Physiol Cogn Med Sci. 1973 Jan;58(1):67–85. doi: 10.1113/expphysiol.1973.sp002192. [DOI] [PubMed] [Google Scholar]
  12. Loudon M. F., Michel C. C., White I. F. The labelling of vesicles in frog endothelial cells with ferritin. J Physiol. 1979 Nov;296:97–112. doi: 10.1113/jphysiol.1979.sp012993. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Luft J. H. Fine structures of capillary and endocapillary layer as revealed by ruthenium red. Fed Proc. 1966 Nov-Dec;25(6):1773–1783. [PubMed] [Google Scholar]
  14. Mason J. C., Curry F. E., Michel C. C. The effects of proteins upon the filtration coefficient of individually perfused frog mesenteric capillaries. Microvasc Res. 1977 Mar;13(2):185–202. doi: 10.1016/0026-2862(77)90084-x. [DOI] [PubMed] [Google Scholar]
  15. Mason J. C., Curry F. E., White I. F., Michel C. C. The ultrastructure of frog mesenteric capillaries of known filtration coefficient. Q J Exp Physiol Cogn Med Sci. 1979 Jul;64(3):217–224. doi: 10.1113/expphysiol.1979.sp002474. [DOI] [PubMed] [Google Scholar]
  16. RENKIN E. M. TRANSPORT OF LARGE MOLECULES ACROSS CAPILLARY WALLS. Physiologist. 1964 Feb;60:13–28. [PubMed] [Google Scholar]
  17. Renkin E. M. Multiple pathways of capillary permeability. Circ Res. 1977 Dec;41(6):735–743. doi: 10.1161/01.res.41.6.735. [DOI] [PubMed] [Google Scholar]
  18. Shea S. M., Karnovsky M. J., Bossert W. H. Vesicular transport across endothelium: simulation of a diffusion model. J Theor Biol. 1969 Jul;24(1):30–42. doi: 10.1016/s0022-5193(69)80004-4. [DOI] [PubMed] [Google Scholar]
  19. Shirahama T., Cohen A. S. The role of mucopolysaccharides in vesicle architecture and endothelial transport. An electron microscope study of myocardial blood vessels. J Cell Biol. 1972 Jan;52(1):198–206. doi: 10.1083/jcb.52.1.198. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Simionescu N., Siminoescu M., Palade G. E. Permeability of muscle capillaries to small heme-peptides. Evidence for the existence of patent transendothelial channels. J Cell Biol. 1975 Mar;64(3):586–607. doi: 10.1083/jcb.64.3.586. [DOI] [PMC free article] [PubMed] [Google Scholar]
  21. Tomlin S. G. Vesicular transport across endothelial cells. Biochim Biophys Acta. 1969;183(3):559–564. doi: 10.1016/0005-2736(69)90169-2. [DOI] [PubMed] [Google Scholar]
  22. Wagner R. C., Williams S. K., Matthews M. A., Andrews S. B. Exclusion of albumin from vesicular ingestion by isolated microvessels. Microvasc Res. 1980 Jan;19(1):127–130. doi: 10.1016/0026-2862(80)90088-6. [DOI] [PubMed] [Google Scholar]

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