Up-regulation of Alzheimer's disease-associated proteins may cause enflurane anesthesia induced cognitive decline in aged rats.
Isoflurane anesthesia can cause post-operative cognitive dysfunction in elderly patients. As an isomer of isoflurane, enflurane may also account for cognitive dysfunction. However, the mechanism of enflurane-induced cognitive dysfunction remains obscure. In this study, we investigated the effects of enflurane anesthesia on cognitive function and the possible roles of β-amyloid protein and phosphorylated tau protein in response to enflurane anesthesia in aged rats. After intraperitoneal injection of enflurane, the Morris water maze and the step-down passive avoidance tests were conducted to test the cognitive ability and memory. The enflurane group showed prolonged escape latency, extended space exploration time and increased number of errors at early stage after enflurane anesthesia, suggesting that enflurane should be responsible for the impairment of cognition in aged rats. In addition, we analyzed the expression level of β-amyloid and phosphorylation level of tau in the hippocampus by immunoblotting. Interestingly, the levels of β-amyloid and phosphorylated tau in the hippocampus increased significantly at early stage and then restored to pre-anesthetic levels. Taken together, our results suggest that increasing of β-amyloid and phosphorylation of tau are important to cause cognitive decline in aged rats during initial stage after enflurane anesthesia.
Division of General Anesthesia, Fengixian Central Hospital, Shanghai Nanfeng Road on the 6600th, Fengxian District, Shanghai, 201499, China.
Haijian
H
Liu
Hao
H
Weng
D000375:Aging; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D018685:Anesthetics, Inhalation / Q000633:toxicity*; D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects / Q000502:physiology; D003071:Cognition / Q000187:drug effects / Q000502:physiology; D003072:Cognition Disorders / Q000139:chemically induced* / Q000378:metabolism*; D004737:Enflurane / Q000633:toxicity*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D015151:Immunoblotting; D008297:Male; D018782:Maze Learning / Q000187:drug effects / Q000502:physiology; D010766:Phosphorylation / Q000187:drug effects; D051381:Rats; D017207:Rats, Sprague-Dawley; D013647:Task Performance and Analysis; D013997:Time Factors; D015854:Up-Regulation / Q000187:drug effects; D016875:tau Proteins / Q000378:metabolism*
D016229:Amyloid beta-Peptides; D018685:Anesthetics, Inhalation; C489131:Mapt protein, rat; D016875:tau Proteins; D004737:Enflurane