Effect of Glutamate on the Vestibulo-Solitary Projection after Sodium Nitroprusside-Induced Hypotension in Conscious Rats.
10.4196/kjpp.2015.19.3.275
- Author:
Li Wei LI
1
;
Guang Shi JIN
;
Yan Zhao YANG
;
Abdul Nasir AMEER
;
Min Sun KIM
;
Byung Rim PARK
;
Yuan Zhe JIN
Author Information
1. Department of Physiology and Pathophysiology, Yanbian University College of Medicine, Yanji 133002, China. y-z-jin@ybu.edu.cn
- Publication Type:Original Article
- Keywords:
c-Fos protein;
Glutamate;
Nucleus tractus solitarius;
Orthostatic hypotension;
Vestibulosympathetic reflex
- MeSH:
Aged;
Animals;
Blood Pressure;
Denervation;
Excitatory Amino Acid Antagonists;
Glutamic Acid*;
Humans;
Hypotension*;
Hypotension, Orthostatic;
Microinjections;
N-Methylaspartate;
Nitroprusside;
Pressoreceptors;
Prevalence;
Rats*;
Receptors, AMPA;
Receptors, Glutamate;
Reflex;
Sodium*;
Solitary Nucleus;
Vestibular Nuclei
- From:The Korean Journal of Physiology and Pharmacology
2015;19(3):275-281
- CountryRepublic of Korea
- Language:English
-
Abstract:
Orthostatic hypotension is most common in elderly people, and its prevalence increases with age. Attenuation of the vestibulo-sympathetic reflex (VSR) is commonly associated with orthostatic hypotension. In this study, we investigated the role of glutamate on the vestibulo-solitary projection of the VSR pathway to clarify the pathophysiology of orthostatic hypotension. Blood pressure and expression of both pERK and c-Fos protein were evaluated in the nucleus tractus solitarius (NTS) after microinjection of glutamate into the medial vestibular nucleus (MVN) in conscious rats with sodium nitroprusside (SNP)-induced hypotension that received baroreceptor unloading via sinoaortic denervation (SAD). SNP-induced hypotension increased the expression of both pERK and c-Fos protein in the NTS, which was abolished by pretreatment with glutamate receptor antagonists (MK801 or CNQX) in the MVN. Microinjection of glutamate receptor agonists (NMDA or AMPA) into the MVN increased the expression of both pERK and c-Fos protein in the NTS without causing changes in blood pressure. These results indicate that both NMDA and AMPA receptors play a significant role in the vestibulo-solitary projection of the VSR pathway for maintaining blood pressure, and that glutamatergic transmission in this projection might play a key role in the pathophysiology of orthostatic hypotension.
