|Williams, Paige - TEXAS A&M UNIV-KINGSVILLE|
|Welsh, Tom - TEXAS A&M UNIVERSITY|
|Laurenz, Jamie - TEXAS A&M UNIV-KINGSVILLE|
Submitted to: American Society of Animal Science Southern Section Meeting
Publication Type: Abstract Only
Publication Acceptance Date: November 6, 2006
Publication Date: N/A
Technical Abstract: This study assessed the pattern of immune and stress response following a LPS challenge. Crossbred pigs (n=28 pigs, 2 males and 2 females from 7 litters) were obtained at weaning (21 to 28 d of age). Pigs were transferred to a climate controlled facility, placed into individual pens and allowed ad libitum access to feed and water. Pigs were allowed to acclimatize for two weeks before LPS challenge. One day prior to challenge, pigs were weighed and non-surgically fitted with jugular catheters. On the following day pigs were infused i.v. with LPS (25 ug/Kg BW) and blood samples collected every 30 min for 1 hour prior to and 6 h following LPS challenge. Serum was analyzed for cortisol, norepinephrine (NE), epinephrine (E), tumor necrosis factor-alpha (TNF-alpha), interleukin-6 (IL-6), and IL-1 beta. There was a time-dependent increase (P<0.01) in concentrations of the proinflammatory cytokines following LPS, with peak values occurring at 1, 2.5, and 3 hours post-LPS for TNF-alpha, IL-6, and IL-1 beta (168±13 ng/mL, 2859±417 pg/mL and 686±114 pg/mL, respectively). Consistent with previous studies, cortisol increased (P<0.01) in a time-dependent manner following LPS with peak values at 3.5 h post-infusion (143±13 ng/mL). Concentrations of NE and E also increased (P<0.01) in a time-dependent manner following LPS with peak values at 15 and 30 min post-LPS (3017±624 and 801±368 pg/mL for NE and E, respectively). There was a positive correlation between peak TNF-alpha and cortisol concentration (r=0.39; P<0.05). However, positive correlations between IL-1 beta, IL-6 and cortisol were found only in females (r=0.54 and 0.83, respectively; P<0.05). No correlations (P>0.30) were found between the catecholamines and IL-6. There was a tendency for NE to be negatively correlated with TNF-alpha concentration (r=-0.30; P=0.13) and E concentration to be positively correlated with IL-1 beta in males (r=0.51; P<0.08). This study is the first to report the temporal pattern of catecholamines following LPS infusion in pigs. Results suggest that both cortisol and the catecholamines modulate the production of inflammatory cytokines during the acute phase response.