Page 11 - 麻醉与监护论坛2015年第11期

Effect of Isoflurane-induced Cognitive Dysfunctionon Adult Rats

Fan Zhang, Zhao-qiong Zhu

Department of Anesthesiology, Affiliated Hospital of Zunyi Medical College, Zunyi 563000, China

Abstract

Background: Declined ability in learning and memory remains one administration for cognitive dysfunction, which may cause harm to our
life. Such postoperative cognitive dysfunction is habitually associated with anesthesia management among surgery .[1,2] Research has shown that the
hippocampus plays an essential role in learning and memory. On the basis above, in this research, we discussed the collection between cognitive
dysfunction and isoflurane anesthesia as well as the potential mechanisms of it, in order to determine whether isoflurane will cause cognitive dysfunction
among adult rats or not.

Methods: All rats were divided randomly into six groups (n=36), group A (control group), group B (02 group), the rest 4 groups of adult rats were
exposed to 2% isoflurane for 2 hours, then recover 2 h, 1d, 7d and 14d respectively after isoflurane anesthesia, all rats were trained to Space navigation
test and Spatial probe test. ELISA was used to detect BDNF (brain-derived neurotrophic factor, BDNF) and NGF (nerve growth factor, NGF) of
hippocampus, also the plasma corticosterone (CORT).

Results: Compared with group A, escape latency and total distance in group 1d were significantly prolonged, the frequency of crossing platform
(P<0.05) was reduced with plasma corticosterones and hippocampal BDNF significantly increased. There were no significant changes in NGF contents
between each group.

Conclusion: After isoflurane anesthesia for 2h, cognitive dysfunction was induced in adult rats temporarily. This change may be caused by higher
plasma corticosterones and hippocampal BDNF.

Key Words: Isoflurane; Cognitive dysfunction; Rats
Corresponding Author: Zhao-qiong Zhu, E-mail: ganzhuzhaoqiong@sina.com

Methods Afterward, took out the brain tissue in order to separate the
hippocampi, after several procedures ,we could determine
Animals BDNF and NGF. To prevent influence caused by diurnal
The animals were purchased from the laboratory variation, all materials are collected between 18:00-20:00.
animal center of Third Military Medical University. They
were adult male Sprague Dawley rats with a mean age of SABC immunohistochemistry technique was used to
10 weeks and weight of 250～280g. (License number: scxk detect CORT, BDNF, NG, SABC kit is provided by Wuhan
2007-0005). These animals were randomized into 6 groups: Boshide biometric-technology limited company.
group A (control group), group B (02 group), adult rats
in group C、D、E and F underwent inhalation of 2% Statistical analysis
isoflurane for 2 hours, then recover 2h, 1d, 7d and 14d statistical calculations were performed with SPSS17.0,
respectively after anesthesia. quantitative data are presented as mean ± standard
deviation(x±s), group comparison used single factor
Morris water maze test analysis of variance, inner group data is compared using
Spatial learning and memory were evaluated in The analysis of variance for repeated measurement data,
Morris water maze. All the SD rats had received training statistical significance was set at P＜0.05.
before at a period of five consecutive days. Rats in group
C、D、E and F were subjected to a 2-hour inhalation of Results
the gas mixture which consists of 1.8~2% isoflurane in
combination with pure oxygen in each induction chamber. All SD female adult rats had smoothly finished the
General anesthesia took effect when tuck-tail reflex of adult whole process with no death. Compared with group A
rats disappear. SD rats in group B inhaled pure oxygen at (table1), SD rats from group D demonstrated an increased
the same concentration for 2 hours. Rats in every group had escape latency, as well as a prolonged path length. (P＜
accomplished Space trial and Probe trial singly. All tests were 0.01）,both the frequency of crossing platform and spatial
performed by personnel unaware of the initial assignment. probing distance decreased （P＜0.05）.In group B, the
frequency of crossing platform decreased（P＜0.05）with
Specimen collecting spatial probing distance increased（P＜0.05）.
We p er for m e d i n t r a p er i ton e a l a n e s t h e s i a on
laboratorial rats with 1%pentobarbital sodium, then took CORT: Compared with group A, group B decreased
out blood of eye socket at 4 degrees centigrade. The plasma sharply（P＜0.01），group D increased remarkably（P
was used to deal with centrifuge at 4000r/min for 15 min， ＜0.01）. Compared with group B, group A、D、E and F
then conserved at 80degrees centigrade to determine CORT. had all increased （P＜0.01）.

BDNF expression: group D exceeded group A and B（P

Laboratory and Clinical Investigation 418 FAM 2013 Jan/Feb Vol.20 Issue 1