Selenium and Vitamin E together improve intestinal epithelial barrier function and alleviate oxidative stress in heat stressed pigs

Heat stress compromises intestinal epithelial barrier integrity of mammals through mechanisms that may include oxidative stress. Our objective was to test whether dietary supplementation with antioxidants, selenium (Se) and Vitamin E (VE), protects intestinal epithelial barrier integrity in heat stressed pigs. Female growing pigs (n = 48) were randomly assigned to four diets containing from 0.2 ppm Se and 17 IU kg⁻¹ VE (control, NRC recommended), to 1.0 ppm Se and 200 IU kg⁻¹ VE for 14 days. Six pigs from each dietary treatment were then exposed to either thermoneutral 20°C or heat stress (35°C, 09.00-17.00/ 28°C, overnight) conditions for two days. Trans-epithelial electrical resistance (TER) and FITC-dextran (4 kDa; FD4) permeability were measured in isolated jejunum and ileum using Ussing chambers. Rectal temperature, respiration rate, and intestinal HSP70 mRNA abundance increased (all P < 0.001), and respiratory alkalosis occurred, suggesting that pigs were heat stressed. Heat stress also increased FD4 permeability and decreased TER (both P<0.01). These changes were associated with changes indicative of oxidative stress, a decreased glutathione peroxidase (GPX) activity and an increased glutathione disulfide (GSSG): glutathione (GSH) ratio (both P < 0.05). With increasing dosage of Se and VE, GPX-2 mRNA (P = 0.003) and GPX activity (P = 0.049) linearly increased, and the GSSG:GSH ratio linearly decreased (P = 0.037) and the impacts of heat stress on intestinal barrier function were reduced (P < 0.05 for both TER and FD4 permeability). In conclusion, an increase of dietary Se and VE mitigated heat stress impacts on intestinal barrier integrity, associated with a reduction in oxidative stress in pigs.

This article is protected by copyright. All rights reserved

from Physiology via xlomafota13 on Inoreader http://ift.tt/1qiyWNI
via IFTTT