Analysis of the Baroreceptor and Vestibular Receptor Inputs in the Rostral Ventrolateral Medulla following Hypotension in Conscious Rats.
Input signals originating from baroreceptors and vestibular receptors are integrated in the rostral ventrolateral medulla (RVLM) to maintain blood pressure during postural movement. The contribution of baroreceptors and vestibular receptors in the maintenance of blood pressure following hypotension were quantitatively analyzed by measuring phosphorylated extracellular regulated protein kinase (pERK) expression and glutamate release in the RVLM. The expression of pERK and glutamate release in the RVLM were measured in conscious rats that had undergone bilateral labyrinthectomy (BL) and/or sinoaortic denervation (SAD) following hypotension induced by a sodium nitroprusside (SNP) infusion. The expression of pERK was significantly increased in the RVLM in the control group following SNP infusion, and expression peaked 10 min after SNP infusion. The number of pERK positive neurons increased following SNP infusion in BL, SAD, and BL+SAD groups, although the increase was smaller than seen in the control group. The SAD group showed a relatively higher reduction in pERK expression when compared with the BL group. The level of glutamate release was significantly increased in the RVLM in control, BL, SAD groups following SNP infusion, and this peaked 10 min after SNP infusion. The SAD group showed a relatively higher reduction in glutamate release when compared with the BL group. These results suggest that the baroreceptors are more powerful in pERK expression and glutamate release in the RVLM following hypotension than the vestibular receptors, but the vestibular receptors still have an important role in the RVLM.
Department of Physiology and Pathophysiology, Yanbian University College of Medicine, Yanji 133002, China.
Yan
Y
Lan
Department of Physiology and Pathophysiology, Yanbian University College of Medicine, Yanji 133002, China.
Huan-Jun
HJ
Lu
Department of Physiology and Pathophysiology, Yanbian University College of Medicine, Yanji 133002, China.
Xian
X
Jiang
Department of Physiology and Pathophysiology, Yanbian University College of Medicine, Yanji 133002, China.
Li-Wei
LW
Li
Department of Physiology and Pathophysiology, Yanbian University College of Medicine, Yanji 133002, China.
Yan-Zhao
YZ
Yang
Department of Cerebral Surgery, Yanbian University College of Medicine, Yanji 133000, China.
Guang-Shi
GS
Jin
Department of Oral Physiology, Wonkwang University College of Dentistry, Iksan 570-749, Korea.
Joo Young
JY
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, Wonkwang University School of Medicine and Brain Science Institute at Wonkwang University, Iksan 570-749, Korea.
Byung Rim
BR
Park
Department of Physiology and Pathophysiology, Yanbian University College of Medicine, Yanji 133002, China.
Yuan-Zhe
YZ
Jin
Baroreceptor; Hypotension; Rostral ventrolateral medulla; Vestibular receptor