Lipopolysaccharide enhances asymmetrical production of cytokines and nitric oxide by left and right cerebral cortical microglial cells in BALB/C mice

Lipopolysaccharide (LPS)‐induced inflammatory factors production by the cerebral cortical glial cells in two sides of the murine brain are different. To determine if microglial cells, a subset of glial cells, are involved in asymmetric production, interleukin‐6 (IL‐6), interleukin‐1 β (IL‐1 β ) and nitric oxide (NO) responses to LPS by microglial cells in the right and left cerebral cortices were examined. Primary microglial cells were isolated from BALB/C neonatal mice, treated with LPS (10 µg ml −1 ) for 24 h and examined for IL‐6, IL‐1 β and NO production. At untreated state, the levels of IL‐6, IL‐1 β and NO showed no statistical difference between left and right. However, after LPS treatment, the levels of IL‐6, IL‐1 β and NO for the right microglial cells was statistically significant higher than the left ( P  < 0·05). Our results denote that enhanced production of IL‐6, IL‐1 β and NO after LPS treatment in microglia is directly proportional to their basal‐state levels, and right cortical microglia produce higher levels of IL‐6, IL‐1 β and NO than left cortical microglia. Copyright © 2011 John Wiley & Sons, Ltd.