Chronic Administration of Monosodium Glutamate under Chronic Variable Stress Impaired Hypothalamic-Pituitary-Adrenal Axis Function in Rats.
10.4196/kjpp.2010.14.4.213
- Author:
Hee Jeong SEO
1
;
Hyang Do HAM
;
Hyung Yong JIN
;
Woo Hyung LEE
;
Hyun Sub HWANG
;
Soon Ah PARK
;
Yong Sung KIM
;
Suck Chei CHOI
;
Seoul LEE
;
Kyung Jae OH
;
Byung Sook KIM
;
Byung Rim PARK
;
Moon Young LEE
Author Information
1. Department of Physiology and Digestive Disease Research Institute, School of Medicine, Wonkwang University, Iksan 570-749, Korea. lmy6774@wku.ac.kr
- Publication Type:Original Article
- Keywords:
Chronic variable stress;
Corticosterone;
Hypothalamic-pituitary-adrenal (HPA) axis;
Monosodium glutamate (MSG);
Open field test
- MeSH:
Adult;
Animals;
Axis, Cervical Vertebra;
Corticosterone;
Decapitation;
Endocrine System;
Humans;
Male;
Mice;
Plasma;
Rats;
Rats, Sprague-Dawley;
Sodium Glutamate;
Water;
Weights and Measures
- From:The Korean Journal of Physiology and Pharmacology
2010;14(4):213-221
- CountryRepublic of Korea
- Language:English
-
Abstract:
The hypothalamic-pituitary-adrenal (HPA) axis is the primary endocrine system to respond to stress. The HPA axis may be affected by increased level of corticotrophin-releasing factors under chronic stress and by chronic administration of monosodium glutamate (MSG). The purpose of this study was to investigate whether chronic MSG administration aggravates chronic variable stress (CVS)-induced behavioral and hormonal changes. Twenty-four adult male Sprague-Dawley rats, weighing 200~220 g, were divided into 4 groups as follows: water administration (CON), MSG (3 g/kg) administration (MSG), CVS, and CVS with MSG (3 g/kg) administration (CVS+MSG). In addition, for the purpose of comparing the effect on plasma corticosterone levels between chronic stress and daily care or acute stress, 2 groups were added at the end of the experiment; the 2 new groups were as follows: naive mice (n=7) and mice exposed to restraint stress for 2 h just before decapitation (A-Str, n=7). In an open field test performed after the experiment, the CVS+MSG group significant decrease in activity. The increase in relative adrenal weights in the CVS and CVS+MSG group was significantly greater than those in the CON and/or MSG groups. In spite of the increase in the relative adrenal weight, there was a significant decrease in the plasma corticosterone levels in the CVS+MSG group as compared to all other groups, except the naive group. These results suggest that impaired HPA axis function as well as the decrease in the behavioral activity in adult rats can be induced by chronic MSG administration under CVS rather than CVS alone.
