International Journal for Vitamin and Nutrition Research (IJVNR) is published by IMR Press from Volume 95 Issue 1 (2025). Previous articles were published by another publisher under a hybrid publishing model, and they are hosted by IMR Press on imrpress.com as a courtesy and upon agreement with Hogrefe.
Neuroprotective and long term potentiation improving effects of vitamin E in juvenile hypothyroid rats
1 Student Research Committee, Department of Physiology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
2 Department of Anatomy and Cell Biology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
3 Neuroscience Research Center, Torbat Heydariyeh University of Medical Sciences, Torbat Heydariyeh, Iran.
4 Division of Neurocognitive Sciences, Psychiatry and Behavioral Sciences Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
5 Department of Physiology, School of Medicine, Isfahan University of Medical Sciences, Isfahan, Iran.
6 Department of Physiology, School of Medicine, Jiroft University of Medical Sciences, Jiroft, Iran.
7 Microanatomy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
8 Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.
Abstract
Protective effects of vitamin E (Vit E) on long term potentiation (LTP) impairment, neuronal apoptosis and increase of nitric oxide (NO) metabolites in the hippocampus of juvenile rats were examined. The rats were grouped (n=13) as: (1) control; (2) hypothyroid (Hypo) and (3) Hypo-Vit E. Propylthiouracil (PTU) was given in drinking water (0.05%) during 6 weeks. Vit E (20 mg/ kg) was daily injected (IP). To evaluate synaptic plasticity, LTP from the CA1 area of the hippocampus followed by high frequency stimulation to the ipsilateral Schafer collateral pathway was carried out. The cortical and hippocampal tissues were then removed to measure NO metabolites. The brains of 5 animals in each group were removed for apoptosis study. The hypothyroidism status decreased the slope, 10–90% slope and amplitude of field excitatory post synaptic potential (fEPSP) compared to the control group (P<0.01–P<0.001). Injection of Vit E increased the slope, 10–90% slope and amplitude of the fEPSP in the Hypo-Vit E group in comparison to the Hypo group (P<0.05–P<0.01). TUNEL positive neurons and NO metabolites were higher in the hippocampus of the Hypo rats, as compared to those in the hippocampus of the control ones (P<0.001). Treatment of the Hypo rats by Vit E decreased apoptotic neurons (P<0.01–P<0.001) and NO metabolites (P<0.001) in the hippocampus compared to the Hypo rats. The results of the present study showed that Vit E prevented the LTP impairment and neuronal apoptosis in the hippocampus of juvenile hypothyroid rats.
Keywords
- Apoptosis
- Hippocampus Vitamin E
- Hypothyroidism
- Long term potentiation
- Nitric oxide