L-carnitine and its possible role in red cell and platelet storage.

The storage of red cells or platelets in the liquid state results in changes in quality over time. These changes are collectively known as the storage lesion and are associated with decreased in vivo viability and functionality. Modification of the components of the liquid milieu could favorably influence these changes. L-carnitine is a naturally occurring compound, which is best known for its role in facilitating the transport of long chain fatty acids across the mitochondrial membrane. An additional role for this compound may also exist as a reservoir of acylcarnitines to replace oxidized fatty acids in membrane phospholipids. In experimental studies, L-carnitine has been shown to reduce hemolysis and to improve in vivo survival in nonleukoreduced red cells. This effect on hemolysis appears to be attenuated by prestorage leukoreduction, but the practical benefit of this effect to transfusion recipients is unclear. L-carnitine has also been shown to reduce glycolysis and maintain a better pH in liquid stored platelets. This effect could result in extended platelet storage to 7 or 10 days. Based on such results, a role for L-carnitine as an additive to improve platelet quality in extended platelet storage is suggested.