76 and 14 kDa polypeptides, two major components released from amphibian urinary bladder epithelium. Localization and potential role.

Several experimental conditions such as antidiuretic hormone (ADH) challenge, apical treatment with phorbol myristate acetate (PMA), and mechanical stretching of the tissue are known to increase the insertion of intramembrane particle aggregates and/or granule exocytosis at the apical border of epithelial cells of amphibian urinary bladders. A constant release of 2 peptides of 76 and 14 kDa apparent molecular mass, respectively, was associated with these treatments. The localization of these 2 polypeptides was assessed by immunofluorescence and electron microscopy immunocytochemistry using fluorescent, peroxidase, and colloidal gold probes.

Immunohistochemical analysis of C3 cleavage fragments, factor H, and the C5b-9 terminal complex of complement in de novo membranous glomerulonephritis occurring in patients with renal transplant.

Fifteen renal biopsies from 13 transplanted patients with de novo membranous nephropathy (DNMN) were investigated by immunofluorescence for the presence of C5b-9 neoantigens of the terminal sequence of complement and for antigens expressed by C3 cleavage fragments. DNMN lesions were classified as stage I, II or III upon light and electron microscopy examination. Seven biopsies were classified as stage I DNMN and 8 stage II-III.

Immunohistochemical study of the C5b-9 complex of complement in human kidneys.

The presence and localization of the C5b-9 neoantigens of the terminal complement sequence, of antigens expressed by cleavage fragments of C3, and of Factor H antigens have been studied by immunohistochemical techniques in morphologically normal adult human kidneys and in biopsy specimens from patients with a wide range of renal diseases with and without immune deposits. In morphologically normal kidneys, C5b-9 neoantigens were observed within all connective matrices (arteriolar media, glomerular basement membrane (GBM), mesangial matrix and tubular basement membrane). The C3d and C3g antigens of the C3dg, and C3bi cleavage fragments of C3 and Factor H antigens were found in similar locations.

Structural and cytochemical differentiation of membrane elements of the apical membrane of amphibian urinary bladder epithelial cells. A label fracture study.

It is now generally accepted that ADH-induced increase in water permeability in responsive epithelia is associated with the insertion of specific structures in the apical membrane of epithelial cells. Up to now, these structures have only been recognized in freeze-fractured preparations and their chemical nature is still unknown. In this study, we used the label-fracture method (Pinto da Silva and Kan, J.

Glomerular and vascular IgG deposits in HgCl2 nephritis: role of circulating antibodies and of immune complexes.

The respective roles of circulating anti-glomerular basement membrane antibodies and of circulating immune complexes in the appearance of glomerular linear and granular IgG deposition during HgCl2-induced glomerulonephritis in the Brown-Norway rat has been studied. Syngeneic kidney transplantations have been performed at various phases of the disease. Results show that circulating antibodies are responsible for linear IgG deposition which did not change to granular deposits during the course of the disease.