Turkish Journal of Geriatrics 2002 , Vol 5, Issue 2
Meral YÜKSEL, Goncagül HAKLAR, A. Süha YALÇIN
Marmara Üniversitesi Tıp Fakültesi Biokimya Anabilim Dalı, 81326 Haydarpaşa İstanbul Alzheimer's disease is an important neurodegenerative disease which affects the aging population, The etiology of Alzheimer's disease is still uncertain, However, a number of studies show that Alzheimer's disease is associated with free radical generation, On the other hand, organotypic slice culture technique is a specific method with the characteristics of synaptic organization, In this method, freshly isolated brain slices ~re carefully transferred to sterile membrane units and kept in a tissue culture incubator, Colchicine is a plant alkaloid which blocks axonal transport by microtubule depolymerization, Lumicolchicine, an isomer of colchicines, fails to mimic this effect and is used for control groups, In this study, we have determined the levels of reactive oxygen species (ROS) and nitric oxide (NO) in an experimental model of Alzheimer's disease which was induced by adding colchicine to organotypic hippocampal slice cultures, Freshly isolated hippocampal slices were incubated in a culture flask for 20 days, At the end of this time, colchicine (10mM) or lumicochicine (10mM) was added to the culture medium and chemiluminescence measurements were made using different probes for ROS and NO, Luminol (0,2 mM) and lucigenin (0,2 mM) were used as chemiluminescence probes for the detection of different free radical species, NO measurements were performed by luminol-H2O2 system, Lactate dehydrogenase (LDH) activity in culture medium and triphenyltetrazolium chloride (TTC) staining of hippocampal slices were used for determining neuronal cell loss, In our experimental Alzheimer's disease model, increased ROS and NO levels were determined in the colchicine group as compared with the lumicolchicine group, LDH activity in the culture medium was 89,3 ± 23,3 U/ml in the colchicine group and 56,2 ± 13.4 U/ml in lumicolchicine group The neuronal cell loss was found to be 82, ± 4,9%; with the TTC method, In our experimental Alzheimer's disease model, we have shown increased free radical generation following axonal degeneration, Therefore, we conclude that colchicine can inhibit the mitochondrial energy metabolism, Induce membrane phospholipid peroxidation and expression of neuronal nitric oxide synthase, Our results with LDH activity and TTC measurements supported the free radical generation in this system, In conclusion, treatment of organotypic hippocampal slice cultures with colchicine, which results in increased levels of ROS and NO, can be used to model Alzheimer's disease. Keywords : Alzheimer's disease, Colchicine, Free radicals, Hippocampus Nitric oxide, Organotypic slice culture