INDENTATIONS OF GLOMERULAR BASEMENT-MEMBRANE IN RENAL DISEASES - LIGHT AND ELECTRON-MICROSCOPIC STUDY ON ULTRATHIN SERIAL SECTIONS

  • 1 January 1976
    • journal article
    • research article
    • Vol. 35  (4) , 327-336
Abstract
Identations of the glomerular basement membrane were observed by light microscopy in ultrathin Epon-embedded serial sections from the renal biopsies of patients who had membranous glomerulonephritis, minimal change glomerulonephritis, acute or resolving exudative glomerulonephritis and focal glomerulonephritis, interstitial nephritis, amyloidosis, rheumatoid arthritis or ankylosing spondylitis. In patients with membranous glomerulonephritis, acute or resolving exudative glomerulonephritis, amyloidosis or rheumatoid arthritis, the occurrence of indentations in the glomerular basement membrane differed significantly from that in controls. The presence of indentations did not correlate with proteinuria, hematuria, leukocyturia, arterial hypertension or with the nephrotic syndrome or its treatment with steroids. Examination of alternate serial sections by light microscopy and EM showed that the indentations that were light microscopically visible corresponded to craters on the epithelial surface of the glomerular basement membrane seen by EM. These craters contained protruding portions of the epithelial cells, extracellular electron-lucent material or electron-dense amorphous or striated membranous material. They were often surrounded by spikelike protrusions of the lamina densa. These indentations might represent solitary remnants of former subepithelial deposits.