Sex differences on solid organ histological characteristics after brain death1

PURPOSE: To investigate gender differences in the evolution of the inflammatory process in rats subjected to brain death (BD). METHODS: Adult Wistar rats were divided into three groups: female; ovariectomized female; and male rats. BD was induced using intracranial balloon inflation and confirmed by maximal pupil dilatation, apnea, absence of reflex, and drop of mean arterial pressure. Six hours after BD, histological evaluation was performed in lungs, heart, liver and kidneys, and levels of inflammatory proteins, estrogen, progesterone, and corticosterone were determined in plasma. RESULTS: In the lungs, females presented more leukocyte infiltration compared to males (p<0.01). Ovariectomized female rat lungs were more hemorrhagic compared to other groups (p<0.001). In the heart, females had higher leukocyte infiltration and tissue edema compared to males (p<0.05). In the liver and kidneys, there were no differences among groups. In female group estradiol and progesterone were sharply reduced 6 hours after BD (p<0.001) to values observed in ovariectomized females and males. Corticosterone levels were similar. CONCLUSIONS: Sex hormones influence the development of inflammation and the status of organs. The increased inflammation in lungs and heart of female rats might be associated with the acute reduction in female hormones triggered by BD.

The Role of Keratinocyte-derived Chemokine in Hemorrhage-induced Acute Lung Injury in Mice

Dominant inflammatory cytokines might be different depending on the underlying causes of acute lung injury (ALI). The role of kertinocyte-derived chemokine (KC), a potent chemoattractant for neutrophils, has not been clearly established in hemorrhage-induced ALI. In this study, lung injury and cytokine expressison were evaluated in LPS- or hemorrhage-induced ALI models of BALB/c mice. The myeloperoxidase activities at 4 hr after hemorrhage and LPS-injection were 47.4+/-13.0 and 56.5+/-16.4 U/g, respectively. NF-kappa B activity peaked at 4 hr after hemorrhage, which was suppressed to the control level by anti-high mobility group B1 (HMGB1) antibody. Lung expressions of TNF-alpha, MIP-2, and IL-1beta were increased by LPS injection. However, there was only a minimal increase in IL-1beta and no expressions of TNF-alpha or MIP-2 in hemorrhage-induced ALI. In contrast, lung KC increased significantly at 4 hr after hemorrhage compared to control levels (83.1+/-12.3 vs. 14.2+/-1.6 pg/mL/mg by ELISA) (P<0.05). By immunohistochemical staining, lung neutrophils stained positive for KC. Increased KC was also observed in bronchoalveolar lavage fluid and plasma. KC plays an important role in hemorrhage-induced ALI.