Involvement of PGE2 and RANTES in Staphylococcus aureus-induced fever in rats.

J Appl Physiol (1985)

Laboratory of Pharmacology, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, São Paulo, Brazil.

Published: November 2012

This study investigated the involvement of prostaglandins and regulated on activation, normal T cell expressed and secreted (RANTES), in fever induced by live Staphylococcus aureus (no. 25923, American Type Culture Collection) injection in rats. S. aureus was injected intraperitoneally at 10(9), 10(10), and 2 × 10(10) colony-forming units (CFU)/cavity, and body temperature (T(b)) was measured by radiotelemetry. The lowest dose of S. aureus induced a modest transient increase in T(b), whereas the two higher doses promoted similar long-lasting and sustained T(b) increases. Thus, the 10(10) CFU/cavity dose was chosen for the remaining experiments. The T(b) increase induced by S. aureus was accompanied by significant decreases in tail skin temperature and increases in PGE(2) levels in the cerebrospinal fluid (CSF) and hypothalamus but not in the venous plasma. Celecoxib (selective cyclooxygenase-2 inhibitor, 2.5 mg/kg po) inhibited the fever and the increases in PGE(2) concentration in the CSF and hypothalamus induced by S. aureus. Dipyrone (120 mg/kg ip) reduced the fever from 2.5 to 4 h and the PGE(2) increase in the CSF but not in the hypothalamus. S. aureus increased RANTES in the peritoneal exudate but not in the CSF or hypothalamus. Met-RANTES (100 μg/kg iv), a chemokine (C-C motif) receptor (CCR)1/CCR5 antagonist, reduced the first 6 h of fever induced by S. aureus. This study suggests that peripheral (local) RANTES and central PGE(2) production are key events in the febrile response to live S. aureus injection. As dipyrone does not reduce PGE(2) synthesis in the hypothalamus, it is plausible that S. aureus induces fever, in part, via a dipyrone-sensitive PGE(2)-independent pathway.

Download full-text PDF

Source
http://dx.doi.org/10.1152/japplphysiol.00936.2011DOI Listing

Publication Analysis

Top Keywords

csf hypothalamus
16
induced aureus
12
aureus
9
fever induced
8
increases pge2
8
reduced fever
8
fever
6
induced
5
pge2
5
hypothalamus
5

Similar Publications

Effects of Paradoxical Sleep Deprivation on MCH and Hypocretin Systems.

Sleep Sci

December 2024

Departamento de Psicobiologia, Escola Paulista de Medicina, Universidade Federal de São Paulo, São Paulo, SP, Brazil.

Melanin-concentrating hormone (MCH) and hypocretins (Hcrt) 1 and 2 are neuropeptides synthesized in the lateral hypothalamic area by neurons that are critical in the regulation of sleep and wakefulness. Their receptors are located in the same cerebral regions, including the frontal cortex and hippocampus. The present study aimed to assess whether 96 hours of paradoxical sleep deprivation alters the functioning of the MCH and hypocretin systems.

View Article and Find Full Text PDF

Investigate the impact of diaphragm sellae competence on surgical outcomes and risk factors for postoperative hypothalamic injury (HI) in patients undergoing endoscopic transsphenoidal surgery (ETS) for infradiaphragmatic craniopharyngiomas (ICs). A retrospective analysis of 54 consecutive patients (2016-2023) with ICs treated by ETS was conducted. All tumors originated from the sellar region inferior to the diaphragm sellae and were classified into two subtypes in terms of diaphragm sellae competence: IC with competent diaphragm sellae (IC-CDS) and IC with incompetent diaphragm sellae (IC-IDS).

View Article and Find Full Text PDF

Psychoneuroimmunology (PNI) advancements may revolutionize personalized medicine by identifying systemic biomarkers that enhance diagnosis and treatment. Inflammatory pathways connect personality traits with cognitive performance, aging-related disorders, and mortality risks. Studies have demonstrated the critical interactions between personality and various biological systems like the hypothalamic-pituitary-adrenal (HPA) axis.

View Article and Find Full Text PDF

Hypothalamic tanycytes internalize ghrelin from the cerebrospinal fluid: Molecular mechanisms and functional implications.

Mol Metab

December 2024

Laboratory of Neurophysiology of the Multidisciplinary Institute of Cell Biology [IMBICE, Argentine Research Council (CONICET) and Scientific Research Commission, Province of Buenos Aires (CIC-PBA), National University of La Plata], La Plata, Buenos Aires, Argentina; Department of Surgical Sciences, Functional Pharmacology and Neuroscience, University of Uppsala, Uppsala, Sweden. Electronic address:

Objective: The peptide hormone ghrelin exerts potent effects in the brain, where its receptor is highly expressed. Here, we investigated the role of hypothalamic tanycytes in transporting ghrelin across the blood-cerebrospinal fluid (CSF) interface.

Methods: We investigated the internalization and transport of fluorescent ghrelin (Fr-ghrelin) in primary cultures of rat hypothalamic tanycytes, mouse hypothalamic explants, and mice.

View Article and Find Full Text PDF
Article Synopsis
  • - The hypothalamus-pituitary axis (HPA) is an uncommon site for metastasis from non-Hodgkin's lymphoma, accounting for less than 0.5% of such cases.
  • - The patient exhibited panhypopituitarism and severe hyponatremia linked to the syndrome of inappropriate antidiuretic hormone (SIADH), along with sudden diabetes insipidus (DI), indicating possible hypothalamic infiltration.
  • - While chemotherapy that can penetrate the blood-brain barrier is the main treatment, surgery and radiotherapy have not shown significant improvements in survival rates, and the overall prognosis remains poor.
View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!