Background: Lipopolysaccharide (LPS)-induced systemic inflammation (SI) is associated with neuroinflammation in the brain, hypotension, tachycardia, and multiple organs dysfunctions. Considering that during SI these important cardiovascular and inflammatory changes take place, we measured the sensitivity of the cardiovascular reflexes baroreflex, chemoreflex, and Bezold-Jarisch that are key regulators of hemodynamic function. We also evaluated neuroinflammation in the nucleus tractus solitarius (NTS), the first synaptic station that integrates peripheral signals arising from the cardiovascular and inflammatory status.
Methods: We combined cardiovascular recordings, immunofluorescence, and assays of inflammatory markers in male Wistar rats that receive iv administration of LPS (1.5 or 2.5 mg kg) to investigate putative interactions of the neuroinflammation in the NTS and in the anteroventral preoptic region of the hypothalamus (AVPO) with the short-term regulation of blood pressure and heart rate.
Results: LPS induced hypotension, tachycardia, autonomic disbalance, hypothermia followed by fever, and reduction in spontaneous baroreflex gain. On the other hand, during SI, the bradycardic component of Bezold-Jarisch and chemoreflex activation was increased. These changes were associated with a higher number of activated microglia and interleukin (IL)-1β levels in the NTS.
Conclusions: The present data are consistent with the notion that during SI and neuroinflammation in the NTS, rats have a reduced baroreflex gain, combined with an enhancement of the bradycardic component of Bezold-Jarisch and chemoreflex despite the important cardiovascular impairments (hypotension and tachycardia). These changes in the cardiac component of Bezold-Jarisch and chemoreflex may be beneficial during SI and indicate that the improvement of theses reflexes responsiveness though specific nerve stimulations may be useful in the management of sepsis.
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http://dx.doi.org/10.1186/s12974-019-1512-6 | DOI Listing |
Mol Neurodegener
January 2025
Department of Neurobiology and Behavior, Charlie Dunlop School of Biological Sciences, University of California, Irvine, CA, 92697-4545, USA.
Background: Apolipoprotein E ε4 (APOE4) is the strongest genetic risk factor for late-onset Alzheimer's disease (LOAD). A recent case report identified a rare variant in APOE, APOE3-R136S (Christchurch), proposed to confer resistance to autosomal dominant Alzheimer's Disease (AD). However, it remains unclear whether and how this variant exerts its protective effects.
View Article and Find Full Text PDFAm J Physiol Lung Cell Mol Physiol
January 2025
Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile.
Chronic intermittent hypoxia (CIH), the main feature of obstructive sleep apnea, heightened chemosensory discharges of the carotid body (CB), which contributes to potentiate the ventilatory hypoxic response and elicits hypertension. We aimed to determine: 1) whether the persistence of cardiorespiratory alterations found in long-term CIH depend on the inputs from the CB and, 2) in what extension the activation of glial cells and neuroinflammation in the caudal region of the nucleus of the Solitary Tract (NTS) requires functional CB chemosensory activity. To evaluate these hypotheses, we exposed male mice to CIH for 60 days.
View Article and Find Full Text PDFBr J Pharmacol
December 2024
Institute of Biomedical Sciences, National Sun Yat-sen University, Kaohsiung, Taiwan.
Brain Behav Immun
January 2025
Department of Anesthesiology, State Key Laboratory of Oncology in South China, Guangdong Provincial Clinical Research Center for Cancer, Sun Yat-sen University Cancer Center, Guangzhou, Guangdong, China. Electronic address:
Ann Clin Microbiol Antimicrob
October 2024
Department of Tuberculosis, The Second Hospital of Nanjing, Nanjing, 211100, China.
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