Effect of lithium on the Polyamine Response in Brain after Stress

Lee, Seong Ryong

Abstract

OBJECTIVE
The present study was designed to identify the stress-induced polyamine (PA) response and its modulation by chronic treatment of lithium in brain (hippocampus) and periphery (liver). METHOD: For immobilization stress, rats (230-250 g, male) were placed in restrainer once daily, for 3h. All biochemical measurements were done 5h after the beginning of immobilization stress application. Stress application was done for 5 days and, after a resting interval of 7 days, rats were subjected to an additional stress. Additional groups were subjected to same stress schedule, but during the 7 day interval, one group received once daily injections of 2.5 mmol/kg lithium chloride subcutaneously, and other received saline.
RESULTS
The putrescine (PU) level was increased after each stress episode. After cessation of the intermittent stress period, an additional stress 7 days later led again to an increase in PU level in brain but not in liver. The later increase in PU level was blocked by lithium treatment during the intervening 7 day interval between stressors.
CONCLUSION
The results suggest that long-term lithium treatment can inhibit an overreactive PA response in brain. So, maladjustment of a stress induced PA response may be a factor to the affective illness and can be target of lithium.