Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats.
Significant evidence supports the role of the vestibular system in the regulation of blood pressure during postural movements. In the present study, the role of the vestibulo-spino-adrenal (VSA) axis in the modulation of blood pressure via the vestibulosympathetic reflex was clarified by immunohistochemical and enzyme immunoassay methods in conscious rats with sinoaortic denervation. Expression of c-Fos protein in the intermediolateral cell column of the middle thoracic spinal regions and blood epinephrine levels were investigated, following microinjection of glutamate receptor agonists or antagonists into the medial vestibular nucleus (MVN) and/or sodium nitroprusside (SNP)-induced hypotension. Both microinjection of glutamate receptor agonists (NMDA and AMPA) into the MVN or rostral ventrolateral medullary nucleus (RVLM) and SNP-induced hypotension led to increased number of c-Fos positive neurons in the intermediolateral cell column of the middle thoracic spinal regions and increased blood epinephrine levels. Pretreatment with microinjection of glutamate receptor antagonists (MK-801 and CNQX) into the MVN or RVLM prevented the increased number of c-Fos positive neurons resulting from SNP-induced hypotension, and reversed the increased blood epinephrine levels. These results indicate that the VSA axis may be a key component of the pathway used by the vestibulosympathetic reflex to maintain blood pressure during postural movements.
Department of Physiology and Pathophysiology, Yanbian University College of Medicine and Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules at Yanbian University, Yanji 133002, China.
Huan-Jun
HJ
Lu
Department of Physiology and Pathophysiology, Yanbian University College of Medicine and Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules at Yanbian University, Yanji 133002, China.
Mei-Han
MH
Li
Department of Physiology and Pathophysiology, Yanbian University College of Medicine and Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules at Yanbian University, Yanji 133002, China.
Mei-Zhi
MZ
Li
Department of Physiology, Wonkwang University School of Medicine and Brain Science Institute at Wonkwang University, Iksan 570-749, Korea.
Sang Eon
SE
Park
Department of Physiology, Wonkwang University School of Medicine and Brain Science Institute at Wonkwang University, Iksan 570-749, Korea.
Min Sun
MS
Kim
Department of Physiology and Pathophysiology, Yanbian University College of Medicine and Key Laboratory of Natural Resources of Changbai Mountain & Functional Molecules at Yanbian University, Yanji 133002, China.
Yuan-Zhe
YZ
Jin
Department of Physiology, Wonkwang University School of Medicine and Brain Science Institute at Wonkwang University, Iksan 570-749, Korea.
Byung Rim
BR
Park
Epinephrine; Glutamate; Intermediolateral cell column; Vestibulo-spino-adrenal axis; Vestibulosympathetic reflex; c-Fos protein