Effect of Sevoflurane and Isoflurane on Post-Anaesthesia Cognitive Dysfunction in Normal and Type II Diabetic Rats

Both animal and human studies have documented cognitive and behavioural impairment after exposure to inhalational anaesthetics. Therefore, the current study was designed to demonstrate if the anaesthetics isoflurane and Sevoflurane can result in postoperative cognition dysfunction in normal and diabetic rats. Sixty male Wister rats aged 12 weeks were divided into 6 groups (n=10); group C (standard control), group CD (diabetic control), group S (sevoflurane anaesthesia), group I (isoflurane anaesthesia), group SD (diabetic sevoflurane anaesthesia) group ID (diabetic isoflurane anaesthesia). Animals were anaesthetized with either 2. 5% sevoflurane or 1.5% isoflurane, respectively, for 2h. 1 week later, animals were undergone cognitive tests in (a Morris water maze, T maze and open field arena), the animals were sacrificed, and hippocampus homogenates were studied for caspase 3 activity by western blot assay. Induction of type II diabetes in CD, SD and ID groups was carried out by feeding on a high-fat diet for 8 weeks before the start of the experiment. During the fourth week, Type II diabetes was induced in the experimental group by a single IP injection of 30 mg/kg STZ. Control (normal and diabetic) rats showed no change in long-term/reference memory, non-spatial working memory, exploratory activity or caspase 3 expression in the hippocampus homogenate. Anaesthesia with isoflurane in normoglycemic rats resulted in a significant decline in long-term/reference memory and non-spatial working memory, while exploratory activity and caspase 3 expressions in hippocampus homogenate showed no change to normal control rats. Both isoflurane and Sevoflurane in diabetic rats demonstrated a decline in long-term/reference memory, non-spatial working memory, exploratory activity and caspase 3 expression in hippocampus homogenate compared with normal control rats. Diabetes revealed significant post-anaesthesia cognitive dysfunction after anaesthesia with Sevoflurane or isoflurane in all the studied domains compared to standard control or diabetic control.