The effect of sevoflurane anesthesia on cognitive function in senile rats and the expression of insulin-like growth factor I in hippocampal CA1 area

Objective To study the effect of sevoflurane anesthesia on cognitive functions in gerontal Sprague-Dawley(SD) rats and the expression of insulin-like growth factor Ⅰ(IGF-Ⅰ) in hippocampal CA1 area.Methods Forty twelve-month-old SD rats of either sex were enrolled.They were randomly divided into 5 groups(n = 8/group): the normal control group(group A);group B and C inhaled 1.5 % sevoflurane 2 h;group D and E inhaled 3.0 % sevoflurane 2 h;group B and D were tested after sevoflurane inhalation 1 day,group C and E were tested after 3.0 % sevoflurane inhalation 7 days.All rats received 1.5 % or 3.0 % sevoflurane in a special glass anesthesia box for 2 hours respectively except the normal control.Y-maze was used to test the ability of learning and memory of rats after sevoflurane inhalation 1 or 7 days at the same moment.Hippocampus were immediately removed after the tests.The left hippocampus was isolated for determination of IGF-Ⅰ mRNA expression with RT-PCR technique.The right hippocampus was isolated for determination of IGF-Ⅰexpression with immunhistochemistry technique.Results In D group,3.0 % sevoflurane induced cognitive decline and decreased IGF-Ⅰ and IGF-Ⅰ mRNA expression significantly at 1 d.But there was no significant difference among other groups.Conclusion The high concentration sevoflurane anesthesia can induce temporary cognitive decline and decrease IGF-Ⅰ expression in hippocampal CA1 area of gerontal rats.It is demonstrated that the endogenous IGF-Ⅰ expression levels declining may play an important role in the development process of cognitive disturbances of senile rats.