Melatonin Improves Postoperative Cognitive Dysfunction in Aged Rats: Relevance of Oxidative Stress, PSD95 and Ca2+/Calmoduline Dependent Protein Kinase

English (OpenAlex)

Aim: Postoperative cognitive dysfunction (POCD) is usually seen in the aged patients in postoperativeperiod. In the present study, we aimed to investigate the effects of melatonin on cognitive and synapticdysfunction and oxidative stress in POCD model constructed by abdominal surgery in aged rats.Material and Methods: Twenty months old male Wistar rats were randomly allocated into the controlgroup, melatonin treated-control group, surgery group and melatonin treated-surgery group. The novelobject recognition test (NORT) was used to assess the postoperative cognitive ability of rats at theend of the experiments. The contents of malondialdehyde (MDA) and reduced glutathione (GSH) wereevaluated in the synaptosomes of hippocampus by spectrophotometric methods. The protein levels ofcalcium-calmodulin dependent protein kinase II (CaMKII) and postsynaptic density protein 95 (PSD95)were measured by using ELISA. .Results: Animals in surgery group showed significant an impairment of novel object recognition memoryin NORT. Surgery group also exhibited increased content of MDA (21.05±3.96) and decreased levelsof GSH (5.86±0.26) and PSD95 (156.04±2.56) in the hippocampus (respectively p=0.012, p