Cultured rat glomerular mesangial cells had relatively simple glycolipid composition which comprised mainly monoglycosylceramide, diglycosylceramide, isoglobotetraosylceramide and GM3. Beside these glycolipids, sulfatide, polar gangliosides and an unknown neutral glycolipid were detected in whole kidney and tubules. Polyclonal antibody against the cultured rat mesangial cells, which induced glomerular injury in vivo, bound specifically with isoglobotetraosylceramide.