Differentially abundant proteins between pair-fed thermal neutral (PFTN) and heat-stressed (HS) pigs at 12 h.

<p>^a Trypsin used to digest all proteins</p><p>^b Positive values indicate an increase in HS pigs. Negative values indicate decrease in HS pigs.</p><p>Differentially abundant proteins between pair-fed thermal neutral (PFTN) and heat-stressed (HS) pigs at 12 h.</p

Categorization and general function information for proteins identified as differentially expressed.

<p>Categorization and general function information for proteins identified as differentially expressed.</p

A representative 2D-DIGE gel from the ileum showing identified proteins.

<p>A total of 45 μg of CyDye labeled protein (15 μg of each CyDye 2, 3, and 5) was loaded onto a 11 cm pH 3–10 IPG strip for the first dimension and the second dimension was run on a 12.5% SDS-PAGE gel. Proteins labeled with CyDye5 are shown.</p

Differentially abundant proteins between thermal neutral (TN) and heat-stressed (HS) pigs at 12 h.

<p>^a Trypsin used to digest all proteins</p><p>^b Positive values indicate an increase in HS pigs. Negative values indicate decrease in HS pigs.</p><p>Differentially abundant proteins between thermal neutral (TN) and heat-stressed (HS) pigs at 12 h.</p

Heat Stress Reduces Intestinal Barrier Integrity and Favors Intestinal Glucose Transport in Growing Pigs

<div><p>Excessive heat exposure reduces intestinal integrity and post-absorptive energetics that can inhibit wellbeing and be fatal. Therefore, our objectives were to examine how acute heat stress (HS) alters intestinal integrity and metabolism in growing pigs. Animals were exposed to either thermal neutral (TN, 21°C; 35–50% humidity; n = 8) or HS conditions (35°C; 24–43% humidity; n = 8) for 24 h. Compared to TN, rectal temperatures in HS pigs increased by 1.6°C and respiration rates by 2-fold (<i>P</i><0.05). As expected, HS decreased feed intake by 53% (<i>P</i><0.05) and body weight (<i>P</i><0.05) compared to TN pigs. Ileum heat shock protein 70 expression increased (<i>P</i><0.05), while intestinal integrity was compromised in the HS pigs (ileum and colon TER decreased; <i>P</i><0.05). Furthermore, HS increased serum endotoxin concentrations (<i>P = </i>0.05). Intestinal permeability was accompanied by an increase in protein expression of myosin light chain kinase (<i>P</i><0.05) and casein kinase II-α (<i>P</i> = 0.06). Protein expression of tight junction (TJ) proteins in the ileum revealed claudin 3 and occludin expression to be increased overall due to HS (<i>P</i><0.05), while there were no differences in claudin 1 expression. Intestinal glucose transport and blood glucose were elevated due to HS (<i>P</i><0.05). This was supported by increased ileum Na⁺/K⁺ ATPase activity in HS pigs. SGLT-1 protein expression was unaltered; however, HS increased ileal GLUT-2 protein expression (<i>P = </i>0.06). Altogether, these data indicate that HS reduce intestinal integrity and increase intestinal stress and glucose transport.</p></div

The effects of 24 h of thermal neutral (TN) or heat stress (HS) conditions on intestinal glutamine transport and digestive enzymes in growing pigs.

a<p>Pigs were exposed for 24 hr to either thermal neutral (TN; 21°C) or heat stress (HS; 35°) conditions. Mean ± S.E.M, n = 8/trt.</p>b<p>Liberated glucose.</p

Ileum and serum inflammatory responses are differentially modulated after 24 h of thermal neutral (TN) or heat stress (HS) conditions in growing pigs.

a<p>Pigs were exposed for 24 hr to either thermal neutral (TN; 21°C) or heat stress (HS; 35°) conditions. Mean ± S.E.M, n = 8/trt.</p

Heat stress conditions (HS; 35°C) alters expression and localization of TJ proteins compared to pigs reared in thermal neutral conditions (TN; 21°C) for 24 hours.

<p>Supplemental figure in support of <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0070215#pone-0070215-t002" target="_blank">Table 2</a>.</p

The effects of 24 hours of either constant thermal neutral conditions (TN; 21°C) or heat stress conditions (HS; 35°C) on a) mucosal HSP70 expression or b) mucosal HIF-1α protein expression in growing pigs.

<p>^a,b<i>P</i><0.05, n = 8/trt.</p

Ileum and colon intestinal integrity is compromised in pigs reared in heat stress (HS) conditions compared to thermal neutral (TN).

a<p>Pigs were exposed for 24 hr to either thermal neutral (TN; 21°C) or heat stress (HS; 35°) conditions. Mean ± S.E.M, n = 8/trt.</p>b<p>Transepithelial electrical resistance (TER).</p>c<p>Apparent permeability coefficient of FITC-Dextran transport (APP).</p