TY - JOUR
T1 - Expression and transport of Angiotensin II AT1 receptors in spinal cord, dorsal root ganglia and sciatic nerve of the rat
AU - Pavel, Jaroslav
AU - Tang, Hui
AU - Brimijoin, Stephen
AU - Moughamian, Armen
AU - Nishioku, Tsuyoshi
AU - Benicky, Julius
AU - Saavedra, Juan M.
N1 - Funding Information:
This study was supported by the Division of Intramural Research Programs, National Institutes of Mental Health, National Institutes of Health, Department of Health and Human Services, USA.
PY - 2008/12/30
Y1 - 2008/12/30
N2 - To clarify the role of Angiotensin II in the regulation of peripheral sensory and motor systems, we initiated a study of the expression, localization and transport of Angiotensin II receptor types in the rat sciatic nerve pathway, including L4-L5 spinal cord segments, the corresponding dorsal root ganglia (DRGs) and the sciatic nerve. We used quantitative autoradiography for AT1 and AT2 receptors, and in situ hybridization to detect AT1A, AT1B and AT2 mRNAs. We found substantial expression and discrete localization of Angiotensin II AT1 receptors, with much higher numbers in the grey than in the white matter. A very high AT1 receptor expression was detected in the superficial dorsal horns and in neuronal clusters of the DRGs. Expression of AT1A mRNA was significantly higher than that of AT1B. AT1 receptor binding and AT1A and AT1B mRNAs were especially prominent in ventral horn motor neurons, and in the DRG neuronal cells. Unilateral dorsal rhizotomy significantly reduced AT1 receptor binding in the ipsilateral side of the superficial dorsal horn, indicating that a substantial number of dorsal horn AT1 receptors have their origin in the DRGs. After ligation of the sciatic nerve, there was a high accumulation of AT1 receptors proximal to the ligature, a demonstration of anterograde receptor transport. We found inconsistent levels of AT2 receptor binding and mRNA. Our results suggest multiple roles of Angiotensin II AT1 receptors in the regulation of sensory and motor functions.
AB - To clarify the role of Angiotensin II in the regulation of peripheral sensory and motor systems, we initiated a study of the expression, localization and transport of Angiotensin II receptor types in the rat sciatic nerve pathway, including L4-L5 spinal cord segments, the corresponding dorsal root ganglia (DRGs) and the sciatic nerve. We used quantitative autoradiography for AT1 and AT2 receptors, and in situ hybridization to detect AT1A, AT1B and AT2 mRNAs. We found substantial expression and discrete localization of Angiotensin II AT1 receptors, with much higher numbers in the grey than in the white matter. A very high AT1 receptor expression was detected in the superficial dorsal horns and in neuronal clusters of the DRGs. Expression of AT1A mRNA was significantly higher than that of AT1B. AT1 receptor binding and AT1A and AT1B mRNAs were especially prominent in ventral horn motor neurons, and in the DRG neuronal cells. Unilateral dorsal rhizotomy significantly reduced AT1 receptor binding in the ipsilateral side of the superficial dorsal horn, indicating that a substantial number of dorsal horn AT1 receptors have their origin in the DRGs. After ligation of the sciatic nerve, there was a high accumulation of AT1 receptors proximal to the ligature, a demonstration of anterograde receptor transport. We found inconsistent levels of AT2 receptor binding and mRNA. Our results suggest multiple roles of Angiotensin II AT1 receptors in the regulation of sensory and motor functions.
KW - Angiotensin II AT and AT receptor types
KW - Dorsal rhizotomy.
KW - Dorsal root ganglia
KW - Renin angiotensin system
KW - Sciatic nerve ligation
KW - Spinal cord
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U2 - 10.1016/j.brainres.2008.09.099
DO - 10.1016/j.brainres.2008.09.099
M3 - Article
C2 - 18976642
AN - SCOPUS:57249096984
SN - 0006-8993
VL - 1246
SP - 111
EP - 122
JO - Brain Research
JF - Brain Research
ER -