Carnitine concentration of red blood cells.

The presence of significant concentrations of carnitine in red blood cells is documented using an assay procedure that is described in detail. Red blood cells can be prepared for assay by simple techniques and stored frozen. The reproducibility of the assay procedure is within acceptable limits. Usefulness of the procedure in an experimental setting has been documented with an investigation of both plasma and red blood cell carnitine concentrations of rats of different ages. Earlier studies have demonstrated that plasma carnitine concentrations are two-fold higher in adult male rats than in adult female rats. In agreement with that data, the adult male rat has a red blood cell carnitine concentration which is two-fold higher than that of adult female rats.