Electron microscopic cytochemical studies of anionic sites in the rat spleen

Citation
H. Ueda et al., Electron microscopic cytochemical studies of anionic sites in the rat spleen, J VET MED S, 63(3), 2001, pp. 287-291
Citations number
28
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Veterinary Medicine/Animal Health
Journal title
JOURNAL OF VETERINARY MEDICAL SCIENCE
ISSN journal
0916-7250 → ACNP
Volume
63
Issue
3
Year of publication
2001
Pages
287 - 291
Database
ISI
SICI code
0916-7250(200103)63:3<287:EMCSOA>2.0.ZU;2-D
Abstract
The distribution patterns of the intensity of negative charge on the free s urfaces (glycocalyx of the plasma membrane) of endothelial cells (ECs) in b lood vessels and reticular cells (RCs) in the splenic cord of the rat splee n were studied by an electron microscopic cytochemical method using polyeth yleneimine (PEI) as a cationic probe. Spleens from adult male rats were per fusion-fixed with 0.5% glutaraldehyde - 4 % paraformaldehyde containing 0.0 5% cetylpyridinium chloride and then perfused with 0.58 PEI at pH 7.4. On t he free surfaces (glycocalyx of the plasma membrane) of the ECs examined, d istinct PEI-positive reactions were observed in blood vessels, such as trab ecular :arteries, central arteries, arterial capillaries, pulp veins and tr abecular veins. These PEI-positive electron-dense substances in the trabecu lar arteries, central arteries, and trabecular veins took the shape of a ba nd of 170-250 nm in thickness. On the other hand, the corresponding ultrast ructure of the ECs lining the splenic sinuses and the RCs in the splenic co rd showed exceedingly weak PEI reactions. The PEI-reactive deposits were si gnificantly thinner than those in the above blood vessels. As the thickness of the electron-dense substances can be related to the density of the nega tive charge, these results suggest that there is a high intensity of negati ve charge on the free surfaces (glycocalyx of the plasma membrane) of ECs i n blood vessels where blood cells and plasma pass into the red pulp ol are discharged from the red pulp. In contrast, the splenic sinuses and RCs, whi ch are the main components of the red pulp, contain weakly negative-charged sites. This may contribute to the microcirculation of the splenic blood ve ssels and elucidate the possible physiological functions of the spleen, suc h as blood storage.