The Characterization of AT1 Expression in the Dorsal Root Ganglia After Chronic Constriction Injury.
To clarify the role of Angiotensin II in the regulation of sensory signaling, we characterized the AT1 expression in neuronal subpopulation of lower lumbar dorsal root ganglia under normal conditions and its alteration in neuropathic pain model. The characterization of AT1 expression was done under control and after the chronic constriction injury induced by four loose ligatures of the sciatic nerve representing the model of posttraumatic painful peripheral neuropathy. Major Angiotensin II receptor type was expressed in approximately 43 % of small-sized and 62 % of large-sized neurons in control. The AT1 overexpression after sciatic nerve ligation lasting 7 days was detected predominantly in small-sized AT1 immunoreactive neurons (about 38 % increase). Chronic constriction injury caused a statistically marked increase in number of the small-sized peptidergic (CGRP immunoreactive) neuronal subpopulation expressing AT1 (about 64 %). The subpopulations of AT1-immunoreactive and nonpeptide-containing primary sensory neurons revealed by IB4 binding, tyrosine hydroxylase- and parvalbumin-immunoreactive neurons were not markedly changed. Our results indicate that: (1) the AT1 overexpression after the chronic constriction injury is an important factor in Angiotensin II-potentiated pain perception; (2) Angiotensin II is involved in pathological mechanisms of neuropathic pain and this effect can be mediated perhaps in combination with other neuropeptides synthesized in the primary sensory neurons.
['Oroszova|Zuzana|Z|', 'Hricova|Ludmila|L|', 'Stropkovska|Andrea|A|', 'Lukacova|Nadezda|N|', 'Pavel|Jaroslav|J|']
D000804:Angiotensin II D000818:Animals D000918:Antibody Specificity D015153:Blotting, Western D002478:Cells, Cultured D003250:Constriction D005455:Fluorescent Antibody Technique D005727:Ganglia, Spinal D005904:Glial Fibrillary Acidic Protein D008159:Lumbar Vertebrae D008297:Male D009457:Neuroglia D017208:Rats, Wistar D044140:Receptor, Angiotensin, Type 1 D012584:Sciatic Nerve D011984:Sensory Receptor Cells
AT1 Dorsal root ganglia Chronic constriction injury Angiotensin II Neuropathic pain Calcitonin gene-related peptide