Metabolite levels in adipose tissue and serum of adipoSPTko mice. Triglycerides (A), phosphatidylcholine (PC) (B), and free fatty acid (FFA) (C) levels of gonadal adipose tissue extracts, normalized to DNA, were determined in 4-week-old mice, n = 3 mice per genotype. Free fatty acid (D) and glycerol (E) levels were determined in the serum from 3-month-old mice, n = 5 control, and n = 7 adipoSPTko. F, sphingomyelin levels were determined in serum (4-week-old mice, n = 6 each genotype). Data represent means ± S.D. Student's t test, ***, p < 0.001.