Effects of lactated Ringer's solutions on human leukocytes.

Background: The standard lactated Ringer's (LR) solution contains racemic lactate, an equal mixture of D(-)- and L(+)-isomers. The aim of this study was to investigate whether racemic LR solution (containing both isomers, dl-LR) differs from LR containing L-isomer only (L-LR).

Methods: Blood from 20 volunteers was incubated for 30 minutes with lactated Ringer's solutions containing the DL- or L-form of lactate, Hank's balanced salt solution, normal saline, and ketone Ringer's (lactate replaced with ketone bodies). Neutrophil "oxidative burst" was measured using flow cytometry. Gene expression of 23 genes associated with leukocyte function was determined with cDNA array technique. The arraying procedure was repeated four times to obtain four sets of data.

Results: Compared with the L-LR and ketone Ringer's, DL-LR causes an increased production of reactive oxygen species by neutrophils and affects expression of leukocyte genes known to be involved in inflammation, cell migration, and apoptosis.

Conclusion: Lactated Ringer's solution in commonly used formulation (racemic mixture, DL-LR) influences neutrophil function and leukocyte gene expression.