High concentration of free trimethyllysine in red blood cells.

A high concentration of a basic unidentified amino compound was found in the blood of rats. It was isolated and identified as N epsilon,N epsilon,N epsilon-trimethyllysine by paper chromatography, thin-layer chromatography, high-performance liquid chromatography and amino acid analyzer. It was localized exclusively in red blood cells in the blood of rats. Free trimethyllysine was also determined in the liver, kidney, spleen, brain, muscle, heart and testis of rat. The concentration of free trimethyllysine in red blood cells was more than 10-times as high as that in the other tissues. This compound in red blood cells was found in different species of animals. The relationship between this free trimethyllysine and carnitine was discussed.