Intestinal mucosal perfusion and integrity are maintained in hypotensive brain dead mice.

Area of Science:

• Physiology
• Gastroenterology
• Transplantation Science

Background:

• Brain death (BD) induces significant hemodynamic and inflammatory changes, potentially impairing organ perfusion and causing damage.
• The intestine is highly susceptible to hypoperfusion, and donor hypotension often prevents intestinal donation.
• Limited data exists on intestinal mucosal integrity and perfusion following brain death.

Purpose of the Study:

• To investigate the effects of brain death on intestinal perfusion and mucosal integrity in a mouse model.
• To assess changes in intestinal tight junction proteins and inflammatory markers after inducing brain death.
• To determine if autoregulatory mechanisms preserve intestinal microcirculation during brain death.

Main Methods:

• Brain death was induced in mice using an epidural balloon catheter.
• Intestinal perfusion was measured using laser Doppler flowmetry (LDF).
• Intestinal injury was evaluated using the Chiu-Park score, morphometry, and analysis of tight junction proteins and inflammatory markers.

Main Results:

• Despite decreased blood pressure in brain death mice, intestinal perfusion remained comparable to sham controls.
• Histological examination revealed minimal to no mucosal injury in brain death mice.
• Tight junction proteins and inflammatory markers showed no significant alterations, indicating maintained mucosal integrity.

Conclusions:

• Brain death may activate intrinsic, autoregulatory mechanisms that protect intestinal microvascular perfusion and mucosal integrity.
• These protective mechanisms can operate even in the presence of mild hypotension following brain death.
• Findings suggest the intestine may tolerate brain death better than previously assumed, with implications for organ donation.