Regional expression of sulfatides in rat kidney: immunohistochemical staining by use of monospecific polyclonal antibodies

Sulfatides(1) are quantitatively prominent glycosphingolipids of rat kidney . In order to gain insight into their possible physiological significance i n this organ, and their possible role in Heymann's nephritis, the main sulf atide components were localized immunohistochemically. The antibodies used recognized the sulfatides Sga11, Stri1, Stri2, and Stet2a. Stri1 epitopes w ere expressed in the brush border of proximal tubuli, whereas Stri2-specifi c immune staining was observed in corti cal and medullar collecting ducts. Both Stri1 and Stri2 were also expressed by interstitial cells of the inner medulla. Stet2a was visualized in epithelia of the distal tubules of Henle 's loop and the juxtaglomerular apparatus, including the macula densa. The mAb Sulph-I, that recognizes the SO3(-)-3Gal beta< epitope of Sga11, semino lipid, and Slac1, prominently stained the cortical and medullar collecting ducts. No sulfatide was immune-stained in the glomerular region. For this r eason, the possibility of a direct involvement of anti-Str1 and Stri2 antib odies in the etiology of Heymann's nephritis appears to be less likely. A s trict correlation between the local sulfatide content, as analyzed by chemi cal estimation, and the sulfatide expression, as observed by immunohistoche mical methods, may not be possible.