ISSN:
0003-276X
Keywords:
Life and Medical Sciences
;
Cell & Developmental Biology
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Medicine
Notes:
A battery of fluorochrome- or peroxidase-coupled lectins, reacting with α-or β-galactose (Gal), terminal N-acetylgalactosamine (GalNAc), or Gal-(β1-3)-GalNAc residues, was used to study the emergence and distribution of cellular glycoconjugates in developing and adult rat glomeruli. Neuraminidase pretreatment of the specimens was applied to monitor the maturation of the glomerular sialogly-coprotein coat.In the adult glomeruli, the lectin conjugates applied reacted sparsely or not at all, but most of them showed an increased reactivity with podocytes and/or the glomerular basement membrane after neuraminidase treatment. In the embryonic glomeruli, lectins reacting with β-Gal residues prominently bound to the basement membranes, as revealed in double-staining with laminin antibodies. This reactivity decreased first during late postnatal development. Some terminal Gal-(β1-3)-GalNAc residues were noted in the earliest podocytes, but obviously soon became covered by sialylation. Furthermore, the developing podocytes prominently displayed α-Gal residues, as marked by Maclura pomifera (MPA) and Jacalin reactivities but not by the GSA-I conjugates. During postnatal maturation these reactivities also decreased. The GalNAc-specific Helix pomatia (HPA) and Helix aspersa (HAA) agglutinins bound to basement membranes of evolving podocytes but later revealed in the podocytes only a Golgi-like cytoplasmic reactivity. These two lectins showed a marked difference in their binding to tubular basement membranes.In lectin blotting experiments of electrophoretically separated polypeptides transferred onto nitrocellulose, the peanut agglutinin (PNA) and MPA conjugates revealed upon neuraminidase treatment a broad Mr 140,000 polypeptide, compatible with podocalyxin, both in isolated developing and adult glomeruli. The MPA conjugate revealed a similar polypeptide in developing glomeruli, even without neuraminidase treatment. Similar experiments with the HPA and HAA conjugates revealed different polypeptides in both adult and developing glomeruli.Obviously, in the rat kidney the maturation of the podocyte sialoglycoprotein coat and the glomerular basement membranes are multiphasic processes that continue even during late postnatal development.
Additional Material:
7 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/ar.1092230310
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