Chronic treatment with the nitric oxide synthase inhibitor, L-NAME, attenuates estradiol-mediated improvement of learning and memory in ovariectomized rats

Azizi-Malekabadi, O. and Hosseini, O. and Saffarzadeh, O. and Karami, O. and Khodabandehloo, O. (2011) Chronic treatment with the nitric oxide synthase inhibitor, L-NAME, attenuates estradiol-mediated improvement of learning and memory in ovariectomized rats. Clinics, 66 (4). pp. 673-679.

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Chronic treatment with the nitric oxide synthase inhibitor, L-NAME, attenuates estradiol-mediated improvement of learning and memory in ovariectomized rats.pdf

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Abstract

INTRODUCTION: The role of ovarian hormones and nitric oxide in learning and memory has been widely investigated. OBJECTIVE: The present study was carried out to evaluate the effect of the nitric oxide synthase (NOS) inhibitor, N (G)-nitro-L-arginine methyl ester ( L-NAME), on the ability of estradiol to improve learning in OVX rats using the Morris water maze. METHODS: Forty rats were divided into five groups: (1) ovariectomized (OVX), (2) ovariectomized-estradiol (OVXEst), (3) ovariectomized- L-NAME 10 (OVX-LN 10), (4) ovariectomized- L-NAME 50 (OVX-LN 50) and (5) ovariectomizedestradiol- L-NAME 50 (OVX-Est-LN 50). The animals in the OVX-Est group were treated with a weekly injection of estradiol valerate (2 mg/kg; i.m.). The OVX-LN 10 and OVX-LN 50 groups were treated with daily injections of 10 and 50 mg/kg L-NAME (i.p.), respectively. The animals in the OVX-Est-LN 50 group received a weekly injection of estradiol valerate and a daily injection of 50 mg/kg L-NAME. After 8 weeks, all animals were tested in the Morris water maze. RESULTS: The animals in the OVX-Est group had a significantly lower latency in the maze than the OVX group (p<0.001). There was no significant difference in latency between the OVX-LN 10 and OVX-LN 50 groups in comparison with the OVX group. The latency in the OVX-Est-LN 50 group was significantly higher than that in the OVX-Est group (p<0.001). CONCLUSION: These results show that L-NAME treatment attenuated estradiol-mediated enhancement of spatial learning and memory in OVX rats, but it had no significant effect in OVX rats without estrogen, suggesting an interaction of nitric oxide and estradiol in these specific brain functions. © 2011 CLINICS.

Item Type: Article
Additional Information: Cited By :16 Export Date: 16 February 2020 Correspondence Address: Hosseini, O.; Neuroscience Research Center, Dept. of Physiology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; email: hosseinim@MUMS.ac.ir
Uncontrolled Keywords: L-NAME Estradiol Learning Memory Morris water maze antiestrogen drug derivative enzyme inhibitor estradiol valerate dienogest estradiol valerate-dienogest estrogen n(g) nitroarginine methyl ester nandrolone nitric oxide synthase animal animal model article behavior drug antagonism drug combination drug effect female maze test ovariectomy randomization rat reaction time Wistar rat Animals Drug Therapy, Combination Enzyme Inhibitors Estrogen Antagonists Estrogens Maze Learning Models, Animal NG-Nitroarginine Methyl Ester Random Allocation Rats Rats, Wistar Spatial Behavior
Subjects: QV pharmacology
Divisions: Mashhad University of Medical Sciences
Depositing User: mr lib7 lib7
Date Deposited: 20 Apr 2020 09:18
Last Modified: 20 Apr 2020 09:18
URI: http://eprints.mums.ac.ir/id/eprint/16932

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