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Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats.

Lu HJ, Li MH, Li MZ, Park SE, Kim MS, Jin YZ, Park BR - Korean J. Physiol. Pharmacol. (2015)

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: 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.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus

The effect of glutamate on levels of blood epinephrine. (A) Effect of microinjection of glutamate receptor agonists or antagonists into the right medial vestibular nucleus (MVN) on levels of blood epinephrine. (B) Effect of microinjection of glutamate receptor agonists or antagonists into the right rostral ventrolateral medullary nucleus (RVLM) on levels of blood epinephrine. The number of animals in each group was 7. Values are mean±SE. *Significant difference from ACSF group (**p<0.01). †Significant difference from ACSF+SNP group (‡p<0.01). Other notations are as in previous figures.
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Figure 5: The effect of glutamate on levels of blood epinephrine. (A) Effect of microinjection of glutamate receptor agonists or antagonists into the right medial vestibular nucleus (MVN) on levels of blood epinephrine. (B) Effect of microinjection of glutamate receptor agonists or antagonists into the right rostral ventrolateral medullary nucleus (RVLM) on levels of blood epinephrine. The number of animals in each group was 7. Values are mean±SE. *Significant difference from ACSF group (**p<0.01). †Significant difference from ACSF+SNP group (‡p<0.01). Other notations are as in previous figures.

Mentions: Secretion of epinephrine was measured following drug modulation of MVN activity in order to measure the functional connectivity between the MVN and the adrenal gland in the control of blood pressure by the vestibular system. Microinjection of glutamate receptor agonists into the MVN was used to induce epinephrine secretion. In rats microinjected with ACSF into the MVN, the level of epinephrine secretion was 77.8±3.0 pg/mL. However, microinjection of glutamate receptor agonists into the MVN significantly increased the epinephrine secretion as compared to ACSF microinjection, with NMDA increasing the levels of epinephrine to 88.2±5.0 pg/mL and AMPA increasing the levels to 97.5±8.3 pg/mL. The effect of glutamate receptor antagonists on epinephrine secretion was also investigated following SNP-induced hypotension. SNP-induced hypotension resulted in increased epinephrine secretion in rats receiving microinjection of ACSF into the MVN when compared to the normotensive rats receiving microinjection of ACSF. Pretreatment with microinjection of ACSF into the MVN raised epinephrine secretion to 91.6±11.2 pg/mL following SNP-induced hypotension, which was higher than the secretion in normotensive rats (77.8±3.0 pg/mL). However, pretreatment with microinjection of glutamate receptor antagonists significantly decreased epinephrine secretion following acute hypotension compared to microinjection of ACSF. Pretreatment with microinjection of MK-801 decreased epinephrine secretion following SNP-induced hypotension to 79.4±7.6 pg/mL, and CNQX decreased it to 72.6±1.2 pg/mL (Fig. 5A).


Functional Connections of the Vestibulo-spino-adrenal Axis in the Control of Blood Pressure Via the Vestibulosympathetic Reflex in Conscious Rats.

Lu HJ, Li MH, Li MZ, Park SE, Kim MS, Jin YZ, Park BR - Korean J. Physiol. Pharmacol. (2015)

The effect of glutamate on levels of blood epinephrine. (A) Effect of microinjection of glutamate receptor agonists or antagonists into the right medial vestibular nucleus (MVN) on levels of blood epinephrine. (B) Effect of microinjection of glutamate receptor agonists or antagonists into the right rostral ventrolateral medullary nucleus (RVLM) on levels of blood epinephrine. The number of animals in each group was 7. Values are mean±SE. *Significant difference from ACSF group (**p<0.01). †Significant difference from ACSF+SNP group (‡p<0.01). Other notations are as in previous figures.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4553402&req=5

Figure 5: The effect of glutamate on levels of blood epinephrine. (A) Effect of microinjection of glutamate receptor agonists or antagonists into the right medial vestibular nucleus (MVN) on levels of blood epinephrine. (B) Effect of microinjection of glutamate receptor agonists or antagonists into the right rostral ventrolateral medullary nucleus (RVLM) on levels of blood epinephrine. The number of animals in each group was 7. Values are mean±SE. *Significant difference from ACSF group (**p<0.01). †Significant difference from ACSF+SNP group (‡p<0.01). Other notations are as in previous figures.
Mentions: Secretion of epinephrine was measured following drug modulation of MVN activity in order to measure the functional connectivity between the MVN and the adrenal gland in the control of blood pressure by the vestibular system. Microinjection of glutamate receptor agonists into the MVN was used to induce epinephrine secretion. In rats microinjected with ACSF into the MVN, the level of epinephrine secretion was 77.8±3.0 pg/mL. However, microinjection of glutamate receptor agonists into the MVN significantly increased the epinephrine secretion as compared to ACSF microinjection, with NMDA increasing the levels of epinephrine to 88.2±5.0 pg/mL and AMPA increasing the levels to 97.5±8.3 pg/mL. The effect of glutamate receptor antagonists on epinephrine secretion was also investigated following SNP-induced hypotension. SNP-induced hypotension resulted in increased epinephrine secretion in rats receiving microinjection of ACSF into the MVN when compared to the normotensive rats receiving microinjection of ACSF. Pretreatment with microinjection of ACSF into the MVN raised epinephrine secretion to 91.6±11.2 pg/mL following SNP-induced hypotension, which was higher than the secretion in normotensive rats (77.8±3.0 pg/mL). However, pretreatment with microinjection of glutamate receptor antagonists significantly decreased epinephrine secretion following acute hypotension compared to microinjection of ACSF. Pretreatment with microinjection of MK-801 decreased epinephrine secretion following SNP-induced hypotension to 79.4±7.6 pg/mL, and CNQX decreased it to 72.6±1.2 pg/mL (Fig. 5A).

Bottom Line: 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.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.

View Article: PubMed Central - PubMed

Affiliation: 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.

ABSTRACT
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.

No MeSH data available.


Related in: MedlinePlus