Structural changes in mouse small intestinal villi following lower body hyperthermia

Area of Science:

• Gastroenterology
• Thermal Biology
• Histopathology

Background:

• Previous studies on exteriorized mouse small intestine loops showed hyperthermia-induced villi shape changes.
• Exteriorization techniques presented limitations including temperature non-uniformity and unknown handling effects on observed damage.

Purpose of the Study:

• To investigate hyperthermic damage to mouse small intestine villi using a refined in situ lower-body heating method.
• To establish the temperature thresholds for specific structural changes in intestinal villi.

Main Methods:

• Mice underwent lower-body heating within a temperature range of 37.5°C to 43.0°C.
• Histopathological analysis was performed to assess structural changes in intestinal villi.
• Damage scoring was conducted to quantify the severity of hyperthermic effects.

Main Results:

• Heating between 37.5°C and 41.0°C caused minimal to moderate changes, with scattered, vertically collapsed villi.
• Conical or rudimentary villi collapse forms were observed starting at 41.5°C, increasing significantly at 42.0°C.
• The most severe damage, including extensive villi collapse, occurred at 43.0°C.

Conclusions:

• Lower-body heating provides a less technically complicated method for studying hyperthermic damage to the small intestine.
• The observed hyperthermic damage patterns are qualitatively similar to those seen with exteriorized loop methods.
• In situ heating resulted in more significant damage compared to exteriorization techniques when heating times were comparable.