Lactosylceramide metabolism in familial hypercholesterolemic renal cells: Effects of a portacaval shunt operation

Urine samples were collected from three (TH, VG, BA) familial hypercholesterolemic (FH) homozygotes before and after portacaval shunt (PS) procedure. The renal proximal tubular (PT) cells were isolated from urinary sediments by discontinuous Ficoll gradient centrifugation. Cells were characterized using immunohistochemical staining methods. Lactosylceramide (LacCer) was analyzed using biochemical methods. The results were: 1) Before PS, 3-20x10⁴ cells/ml urine were found. After PS, there was a time dependent decrease in the excretion of cells. Three weeks after PS, 0.6-1.0x10⁴ cells/ml urine were found. 2) Before PS, cells contained Papanicolaou (PAP) stain positive cytoplasmic vesicles (CV) which were strongly positive with FITC-LacCer antibody. After PS, there was a gradual decline in PAP stain positive CV and reaction with FITC-LacCer antibody and the appearance of vacuoles in cells. Three weeks after PS, all cells were vacuolated and did not show fluorescence with FITC-LacCer antibody. 3) Before PS, LacCer was the major cell glycosphingolipid After PS, LacCer levels decreased markedly. Our studies reveal that PS decreased the urinary excretion of LacCer contained with PT cells in FH homozygotes.