Effect of protein kinase B on the learning and memory functions of mice with chronic lead exposure

Abstract

Objective To assess the effect of protein kinase B(PKB)on the learning and memory functions of mice with chronic lead exposure. Methotis Since the first day after birth,50 Kunming mice were randomized into 5 groups(n=10)and exposed to a 6-week acetic lead exposure at the concentrations of 1.2,2.4,4.8,7.2,and 9.6 mmol/L administered in the drinking water,with another 10 having normal water as the control group.After the 6-week exposure.water maze test Was performed to assess the spatial learning and memory abilities of the mice.The total PKB(t-PKB) and phosphorylated PKB(p-PKB)in the cortical brain neurons were determined with Western bloRing.Results The mean latency of finding the platform in the lead exposure groups was significantly higher than that in the control group(P＜0.05).Chronic acetic lead exposure resulted in obviously impaired spatial learning and memory ability in the mice,and the severity ofthe damage was positively correlated to lead concentrations in the blood and brain tissue(r=678,P=0.000;r=0.643,P=0.000).Lead exposure caused a significant dose-dependent reduction in P-PKB level in the cortical neurons,and p-PKB level in the cortical neurons was inversely correlated to blood lead concentrations(r=0.820,P=0.028) and to the spatial learning and memory ability(r=-0.671,p=000).The level of t-PKB in the cortical brain neurons showed no significant changes in response to lead exposure. Conclusion Chronic acetic lead exposure can impair the learning and memory functions of mice possibly in association with reduced content of p-PKB in the cortical brain neurons. Key words: Protein kinase B; Lead intoxication; Cortical neuron