Effect of selenium as a protective agent during ischemia injury induced in transplant organs

Abstract

Selenium is an essential element in human and animal metabolism, which is found as a constituent of selenoproteins. Selenium in selenocysteine form is integrated into the catalytic site of glutathione peroxidase (GPx), an antioxidant enzyme that protects the cells from the damage caused by reactive oxygen species (ROS). Oxidative stress is the imbalance between ROS and antioxidant defense systems, generating alterations of DNA, proteins, and lipid peroxidation. The imbalance occurs particularly during ischemia and lack of postmortem perfusion. This mechanism is of relevance in organs transplant, it affects the outcome during surgeries. The aim of this research was to evaluate the effect of selenium as a protective agent during ischemia injury induced postmortem in organs. Wistar rats (N=20) were administered via oral 75 μg/kg/day of seleno-methionine (Se-Met) during 7, 14, and 21 days. After sacrificed, the liver, heart, and kidney samples were collected at different postmortem intervals PMI (0-1-3-6-12 h). Total selenium concentration in organs was determined by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). The administration of Se-Met produced a significant increase of selenium concentration in the liver (65%, P<0.001), heart (40%, P<0.01), and kidney (45%, P<0.05) respect to control. At 21 days, selenium showed significantly higher levels in kidney than control animals (3.75±0.24 vs.2.02±0.37 mg/kg, P<0.01). Oxidative stress was measured by malondialdehyde (MDA) liquid chromatography. The MDA decreased significantly in the heart (0.21±0.04 vs. 0.12±0.02 mmol/g) and the kidney (0.41±0.02 vs. 0.24±0.03 mmol/g) at one-hour PMI (P<0.01). Organs removed at different PMI intervals showed lower production of MDA compared to the control group (P<0.05). Se-Met decreased significantly oxidative stress in transplant organs from 1 to 12 h PMI. The results suggest that selenium is a protective agent that improves transplant organs‟ survival and the outcome of transplant surgeries. Future studies will be focused on the specific activity of GPx and selenium in transplant organs.