Abstract
In addition to their role in cardiorespiratory regulation, carotid body (CB) chemoreceptors serve as sensors for inflammatory status and as a protective factor during sepsis. However, lipopolysaccharide-induced sepsis (LPS) reduces CB responsiveness to excitatory or depressant stimuli. We tested whether LPS exerts a direct effect on the carotid chemoreceptor pathway, the CB and its sensory ganglion. We determined that the rat CB and nodose-petrosal-jugular ganglion complex (NPJgc) express TLR4, TNF-α and its receptors (TNF-R1 and TNF-R2). LPS administration (15. mg/kg intraperitoneally) evoked MyD88-mechanism pathway activation in CB and NPJgc, with NF-κB p65, p38 MAPK, and ERK activation. Consistently, LPS increased TNF-α and TNF-R2. Double-labeling studies showed that the aforementioned pathway occurs in TH-containing glomus cells and NPJgc neurons, components of the chemosensitive neural pathway. Thus, our results suggest that LPS acting directly through TLR4/MyD88-mechanism pathways increases TNF-α and TNF-R2 expression in the carotid chemoreceptor pathway. These results show a novel afferent pathway to the central nervous system during endotoxemia, and could be relevant in understanding sepsis pathophysiology and therapy.
Original language | English |
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Pages (from-to) | 336-348 |
Number of pages | 13 |
Journal | Respiratory Physiology and Neurobiology |
Volume | 175 |
Issue number | 3 |
DOIs | |
State | Published - 15 Mar 2011 |
Externally published | Yes |
Bibliographical note
Funding Information:This work was supported by grants DI-02-06/R and DI-39-09/R (to RF), and DI 40-09/R (to FS) from the Division for Research of the Universidad Andres Bello (UNAB) . Thanks are due to Ms. Valentina Squicciarini and to Mr. Patrick Alvarez, for their assistance during some experiments. Special thanks go to Mr. George Montgomery for proofreading the manuscript.
Keywords
- Carotid body
- LPS
- MyD88-dependent
- Sepsis
- TLR4
- TNF-α