| ORIGINAL ARTICLE
|Year : 2022 | Volume
| Issue : 2 | Page : 548--553
Protective Effect of L-Arginine in an Animal Model of Alzheimer's Disease Induced by Intra-Hippocampal Injection of AlCl3
Manizheh Karami1, Samira Geravand2, Mahnaz Rahimpour2
1 Neurophysiology Research Center; Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
2 Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran, Iran
Background and Objective: Aluminum chloride (AlCl3) can impair spatial memory recovery. We investigated the protective effect of L-arginine, a precursor of nitric oxide (NO), on memory retrieval in an Alzheimer's animal model induced by AlCl3 at intra-hippocampal CA1 using a seeking behavior practice.
Materials and Methods: Wistar rats were deeply anesthetized and cannulated at CA1 (AP: -3.8 mm, L: ±2.2 mm, V: 3 mm), and received once AlCl3 (1–200 μg/rat, intra-CA1), on day of cannulation under stereotaxic device. After a week of recovery, they experienced the novelty task with a three-stage paradigm and injected L-arginine (0.05–25 μg/rat) intra-CA1, pretesting. L-NAME, the neuronal NO synthase inhibitor was administered before L-arginine effective doses in the test stage. Also, a reference group exclusively received beta-amyloid 2 μg/rat. Control group solely received saline. Finally, after euthanasia of rat, the hippocampal sample was collected on ice and evaluated by immunohistochemical marking and specific staining.
Results: AlCl3 caused novelty-seeking behavior without meaningful change in animal locomotor activity. βA (2 μg/rat, intra-CA1) affected the rat's grooming, causing it to stop further in the new side. Pretest injection of L-arginine restored behavior in AlCl3-treated rats; however, this effect was stopped by L-NAME pretreatment, indicating NO involvement. CA1 did not show necrotic change due to AlCl3 exposure; however, neurofibrillary tangles were accumulated in the region.
Conclusions: Prophylaxis with L-arginine probably due to NO has a protective role against the dangerous effect of AlCl3 on the function of neurons in the cortical hippocampus.
Dr. Manizheh Karami
Department of Biology, Faculty of Basic Sciences, Shahed University, Tehran
Source of Support: None, Conflict of Interest: None
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