The carotid body detects circulating tumor necrosis factor-alpha to activate a sympathetic anti-inflammatory reflex

Author(s)

Katayama, Pedro L. ; Leirao, Isabela P. ; Kanashiro, Alexandre ; Luiz, Joao P. M. ; Cunha, Fernando Q. ; Navegantes, Luiz C. C. ; V. Menani, Jose ; Zoccal, Daniel B. ; Colombari, Debora S. A. ; Colombari, Eduardo

• Document type: Journal article
• Source: BRAIN BEHAVIOR AND IMMUNITY; v. 102, p. 17-pg., 2022-03-25.

Abstract

Recent evidence has suggested that the carotid bodies might act as immunological sensors, detecting pro-inflammatory mediators and signalling to the central nervous system, which, in turn, orchestrates autonomic responses. Here, we confirmed that the TNF-alpha receptor type I is expressed in the carotid bodies of rats. The systemic administration of TNF-alpha increased carotid body afferent discharge and activated glutamatergic neurons in the nucleus tractus solitarius (NTS) that project to the rostral ventrolateral medulla (RVLM), where many pre-sympathetic neurons reside. The activation of these neurons was accompanied by an increase in splanchnic sympathetic nerve activity. Carotid body ablation blunted the TNF-alpha-induced activation of RVLM-projecting NTS neurons and the increase in splanchnic sympathetic nerve activity. Finally, plasma and spleen levels of cytokines after TNF-alpha administration were higher in rats subjected to either carotid body ablation or splanchnic sympa-thetic denervation. Collectively, our findings indicate that the carotid body detects circulating TNF-alpha to activate a counteracting sympathetic anti-inflammatory mechanism. (AU)

• FAPESP's process: 19/11196-0 - Mechanisms and neural circuits involved in the interaction between peripheral inflammation and sympathoexcitation in Renovascular Hypertension
• Grantee: Pedro Lourenço Katayama
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• FAPESP's process: 15/23467-7 - Experimental pathophysiology: role of central mechanisms of the cardiovascular and respiratory control changes induced by experimental hypertension and obesity
• Grantee: Eduardo Colombari
• Support Opportunities: Research Projects - Thematic Grants