Brain death and changes in solid organ characteristics due to acute lack of female sex hormones

Introduction

Previous studies have suggested that female sex hormones have a protective action, because they contribute to reduce the inflammatory degree in females after trauma.

Objective

This study aimed to investigate sex differences in the course of the inflammatory process in rats subjected to brain death (BD).

Methods

Wistar rats were randomized into three groups (male rats, n = 5; female rats, n = 10; and ovariectomized rats, n = 5) and subjected to BD by rapid inflation of a catheter Fogarty^® 4F. The liver, kidneys, lungs and the heart were collected after 6 hours and samples (4 µm) were stained with H&E for histological analyses. Leukocyte infiltration, edema and hemorrhage were measured and data were compared using GraphPad Prism v.6.10, and p values lower than 0.05 were considered significant.

Results

Female rats exhibited increased leukocyte infiltration into the lungs and the heart when compared with male rats (p = 0.009 in the lungs and p = 0.022 in the heart) and presented also a sudden decrease in estradiol levels 6 hours after BD (p = 0.01). The intensity of hemorrhage was greater in ovariectomized rats compared with the other groups (p = 0.001) in the lungs. All groups presented slight to moderate leukocyte infiltration and absence to slight hemorrhage in the liver. Leukocyte infiltration had a wide distribution in female rat kidneys, and in male and ovariectomized rat kidneys infiltration varied from absent to slight.

Conclusion

The increased inflammation in the lungs and heart of female rats might be a result of the lack of female sex hormones. Therefore, the idea of introducing a therapeutic use of female sex hormones on female BD donors could be considered.