Effect of atenolol pre-treatment in heart damage in a model of intestinal ischemia-reperfusion

Gut-Derived Exosomes Induce Liver Injury After Intestinal Ischemia/Reperfusion by Promoting Hepatic Macrophage Polarization

Liver injury induced by intestinal ischemia/reperfusion (I/R) is accompanied by the polarization of Kupffer cells, which are specialized macrophages located in the liver. However, the causes of hepatic macrophage polarization after intestinal I/R remain unknown. This study investigated whether gut-derived exosomes contribute to the pathogenesis of liver injury triggered by intestinal I/R in a murine model and explored the underlying mechanisms. Intestinal I/R models were established by temporally clamping the superior mesenteric arteries of mice. Exosomes were isolated from the intestinal tissue of mice that underwent intestinal I/R or sham surgery according to a centrifugation-based protocol. Exosomes were co-cultured with RAW 264.7 macrophages or injected intravenously in mice. Liposomal clodronate was administered intraperitoneally to deplete the macrophages. Macrophage polarization was determined by flow cytometry, immunohistochemistry, and quantitative polymerase chain reaction. Liver injury was assessed by histological morphology and increased serum aspartate aminotransferase and alanine aminotransferase levels. Exosomes from mice intestines subjected to I/R (IR-Exo) promoted macrophage activation in vitro. Intravenous injection of IR-Exo caused hepatic M1 macrophage polarization and led to liver injury in mice. Depleting macrophages ameliorated liver injury caused by intestinal I/R or the injection of IR-Exo. Furthermore, inhibiting exosome release improved intestinal injury, liver function, and survival rates of mice subjected to intestinal I/R. Our study provides evidence that gut-derived exosomes induce liver injury after intestinal I/R by promoting hepatic M1 macrophage polarization. Inhibition of exosome secretion could be a therapeutic target for preventing hepatic impairment after intestinal I/R.

EFFECT OF COPAIBA OIL IN INTESTINAL MUCOSA OF RATS SUBMITTED TO HYPOVOLEMIC SHOCK

Background:

Hypovolemic shock is a common disease in polytrauma patients and may develop ischemia in various organs, increasing morbidity and mortality. The bowel is usually most affected by this condition.

Aim:

To evaluate the effects of copaiba oil on the intestinal mucosa’s injury of rats submitted to hypovolemic shock.

Method:

Fifteen rats were divided into three groups: sham - simulated surgery; ischemia - animals submitted to hypovolemic shock; and copaiba - animals submitted to hypovolemic shock previously treated with copaiba oil. Mean blood pressure, arterial blood gas after shock induction, degree of intestinal lesion and villus length were evaluated.

Results:

The sham presented the lowest values of lactate and PaCO₂ and the highest values of mean arterial pressure, pH and bicarbonate in relation to the other groups. The degree of mesenteric lesion was zero in the sham group; 3.00±1.00 in the ischemia group; and 3.00±0.71 in the copaiba group. The villus length was 173.60±8.42 in the sham, 142.77±8.33 in the ischemia and 143.01±9.57 in the copaiba group. There was a significant difference between the sham and the other groups (p<0.05); however, there not significant difference between groups Ischemia and copaiba.

Conclusion:

Administration of copaiba oil did not reduce the intestinal mucosa lesion of rats after hypovolemic shock.