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Anaphylactic hypotension causes renal and adrenal sympathoexcitaion and induces c-fos in the hypothalamus and medulla oblongata.
- Source :
-
Experimental physiology [Exp Physiol] 2018 Jun; Vol. 103 (6), pp. 790-806. Date of Electronic Publication: 2018 Apr 19. - Publication Year :
- 2018
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Abstract
- New Findings: What is the central question of this study? Whether anaphylaxis affects sympathetic outflows to the brown adipose tissue (BAT) and adrenal gland and whether anaphylaxis affects some brain areas in association with sympathetic regulation. What is the main finding and its importance? Sympathoexcitatory responses to anaphylaxis occurred regionally in the kidney and adrenal gland, but not in the thermogenesis-related BAT. Further, anaphylactic hypotension also caused increase in c-fos immunoreactivity in the hypothalamic and medullary areas. Moreover, catecholaminergic neurons of the brainstem cause adrenal sympathoexcitation in a baroreceptor-independent manner.<br />Abstract: We previously reported that sympathetic nerve activity (SNA) to the kidney and the hindlimb increases during anaphylactic hypotension in anaesthetized rats. Based on this evidence, we examined effects of anaphylactic hypotension on SNA to the brown adipose tissue (BAT), and the adrenal gland and kidney in anaesthetized rats. We demonstrated that adrenal and renal SNA, but not BAT-SNA, were stimulated. In addition, the effects of anaphylaxis on neural activities of the hypothalamic and medullary nuclei, which are candidates for relaying efferent SNA to the peripheral organs, were investigated via immunohistochemical staining of c-fos. Anaphylaxis increased c-fos expression in the neurons of the paraventricular nucleus (PVN) of the hypothalamus and in those of the nucleus tractus solitarii (NTS) and rostral ventrolateral medulla (RVLM) of the medulla oblongata; c-fos was expressed in γ-aminobutyric acid (GABA)-ergic neurons of the NTS and in the catecholaminergic neurons of the RVLM. In addition, c-fos expression in the rostral NTS and mid NTS during anaphylaxis was reduced by sinoaortic baroreceptor denervation; however, increased c-fos expression in the caudal NTS and RVLM or adrenal sympathoexcitation were not affected by sinoaortic baroreceptor denervation. These results indicated that anaphylactic hypotension activates the hypothalamic PVN and the medullary NTS and RVLM independently of the baroreflex pathway. Further, it stimulated efferent SNA to the adrenal gland and kidney to restore blood pressure.<br /> (© 2018 The Authors. Experimental Physiology © 2018 The Physiological Society.)
- Subjects :
- Adipose Tissue, Brown metabolism
Adipose Tissue, Brown physiopathology
Animals
Baroreflex physiology
Blood Pressure physiology
Denervation methods
Kidney metabolism
Male
Neurons metabolism
Neurons physiology
Paraventricular Hypothalamic Nucleus metabolism
Pressoreceptors metabolism
Pressoreceptors physiopathology
Rats
Rats, Sprague-Dawley
Solitary Nucleus metabolism
Sympathetic Nervous System metabolism
Thermogenesis physiology
Anaphylaxis physiopathology
Hypotension physiopathology
Kidney physiopathology
Paraventricular Hypothalamic Nucleus physiopathology
Proto-Oncogene Proteins c-fos metabolism
Solitary Nucleus physiopathology
Sympathetic Nervous System physiopathology
Subjects
Details
- Language :
- English
- ISSN :
- 1469-445X
- Volume :
- 103
- Issue :
- 6
- Database :
- MEDLINE
- Journal :
- Experimental physiology
- Publication Type :
- Academic Journal
- Accession number :
- 29524326
- Full Text :
- https://doi.org/10.1113/EP086809