Blood-cerebrospinal fluid barrier in hyperthermia

Area of Science:

• Neuroscience
• Physiology

Background:

• The blood-CSF barrier (BCSFB) and blood-brain barrier (BBB) maintain CNS homeostasis.
• Dysfunction of these barriers leads to ion, water, and protein influx into the CNS, causing edema.
• Hyperthermia's effects on BCSFB are less understood than BBB.

Purpose of the Study:

• To investigate the impact of whole body hyperthermia (WBH) on BCSFB integrity and function.
• To explore the role of cyclooxygenase (COX) pathways in heat-induced BCSFB disruption.
• To assess the consequences of BCSFB damage on CNS tissue.

Main Methods:

• Utilized a rat model subjected to heat stress (38°C for 4 hours).
• Assessed BCSFB permeability using Evans blue and (131)Iodine translocation.
• Examined histological changes in choroidal epithelium, ependyma, and brain tissue.

Main Results:

• WBH significantly increased plasma-to-CSF translocation of Evans blue and (131)Iodine.
• Heat stress induced degeneration of choroidal epithelial and ependymal cells.
• BCSFB disruption correlated with increased edema in the hippocampus, thalamus, and hypothalamus.

Conclusions:

• The BCSFB is vulnerable to WBH, leading to increased fluid and ion transfer into the brain.
• Heat-induced BCSFB breaching significantly contributes to CNS cell and tissue injury.
• Inhibition of COX pathways may offer a therapeutic strategy against hyperthermia-induced brain damage.