Renal GSLs were quantified in renal cortex homogenates from the same mice as in Fig 1 at the endpoint of the study. (A) Ceramides (Cers). (B) Hexosylceramides (HexCers). (C) Lactosylceramides (LacCers). Major chain length species (C16, C22, C24, C24:1) and total of all chain-lengths (Total) of each lipid presented for each animal are presented in the graphs. (D) Neuraminidase (NEU) activity was quantified in kidney cortex homogenates. NEU activity (absorbance, Abs) was quantified within each homogenate at 15 min intervals, normalized to total protein, and presented as average absorbance per mg protein for each time point. HexCers (E) and LacCers (F) were measured in 24-hr urine collections at the endpoint of the study and normalized to urine creatinine (UCr). Means with standard deviations are provided for all graphs. Water, water-treated MRL/lpr mice; OP, OP-treated MRL/lpr mice; MpJ, MRL/MpJ (untreated) mice.