Individual ceramide species were measured by LC/ESI-MS/MS in plasma (A) and kidney tissue (B) from 24 wk old control (db/+) and diabetic (db/db) mice by MS. Data was log2 transformed, normalized by plasma volume (μl) or tissue weight (mg), and is expressed as the relative log fold change in diabetic mice compared to control. Box-and-whiskers plots display distributions of each metabolite. The length of the box defines the interquartile range (IQR) while the whiskers denote the maximum and minimum value. The line in each box represents the median. * p < 0.05. Pearson’s correlation was used to define a relationship between plasma and kidney tissue levels per mouse. Linear regression models for ceramide species with a significant correlation (p < 0.05) are shown (C-D). In the nomenclature (Cer C16:0), the number before the colon refers to length of the carbon chain and the number after the colon to the number of double bonds in the chain.
