Figure 2. Levels of acylcarnitine species and carnitine biosynthesis intermediates in plasma of wild-type (WT) mice (white boxes) and MTKO mice (gray boxes). (A) N6,N6,N6-trimethyl-L-lysine (TML) level at 50 weeks of age; (B) Levels of L-carnitine [C0] and acylcarnitine species (L-acetylcarnitine [C2], Hexanoylcarnitine [C8], Decanoylcarnitine [C10], Tetradecanoylcarinitne [C14], 3,5-Tetradecadiencarnitine [C14:2], L-Palmitoylcarnitine [C16], 9-Hexadecenoylcarnitine [C16:1], Oleoylcarnitine [C18:1], Arachidonoylcarnitine [C20:4]) at 100 weeks of age; (C) TML level at 100 weeks of age; (D) Level of γ-butryobetaine (γ-BB), also known as 4-trimethylammoniobutanoic acid, at 100 weeks of age. The box denotes 25th and 75th percentiles; the line within the box denotes the 50th percentile; the whisker denotes standard deviation. (n = 3). *P < 0.05 and **P < 0.01. (E) Carnitine biosynthesis pathway. HTML, 3-hydroxyl-N6-trimethyl-L-lysine; TMABA, 4-trimethyl-aminobutyraldehyde; TML dioxygenase, TMLD; HTML aldolase, HTMLA; TMABA dehydrogenase, TMABADH; γ-BB dioxygenase, BBD.