Increase in rat intestinal permeability to endotoxin during hyperthermia

Area of Science:

• Physiology
• Gastroenterology
• Toxicology

Background:

• Heat stroke shares clinical features with endotoxemia.
• The role of intestinal permeability in heat stroke pathophysiology is unclear.

Purpose of the Study:

• To investigate if hyperthermia increases intestinal wall permeability to endotoxin.
• To determine if heat stress damages the intestinal membrane, leading to endotoxin leakage.

Main Methods:

• Rats were subjected to heat stress to induce hyperthermia.
• Segments of intestine from heat-stressed and non-stressed rats were incubated with 125I endotoxin at 37°C or 45°C.
• Endotoxin leakage was measured to assess intestinal permeability.

Main Results:

• Intestinal segments from heat-stressed rats showed three times greater endotoxin leakage compared to non-stressed rats.
• Incubating non-stressed intestinal segments at 45°C also resulted in significantly increased endotoxin leakage.
• These findings indicate heat damages the intestinal membrane.

Conclusions:

• Heat stress increases intestinal permeability to endotoxins.
• This increased gut permeability and subsequent endotoxin leakage may be a contributing factor to the development of heat stroke.