Author:

Keywords:

Science & Technology, Life Sciences & Biomedicine, Agriculture, Dairy & Animal Science, Agriculture, intestinal integrity, tight junction, AMP-activated protein kinase, heat stress, broiler, INTESTINAL BARRIER DYSFUNCTION, GROWTH-PERFORMANCE, PROBIOTIC MIXTURE, STRESS, TEMPERATURE, MECHANISMS, EXPRESSION, OCCLUDIN, OLIGOSACCHARIDES, MORPHOLOGY, AMP-Activated Protein Kinases, Animals, Avian Proteins, Chickens, Hot Temperature, Jejunum, Male, Random Allocation, Tight Junction Proteins, Tight Junctions, 0605 Microbiology, 0702 Animal Production, 0908 Food Sciences, Dairy & Animal Science, 3003 Animal production, 3006 Food sciences, 3009 Veterinary sciences

Abstract:

Dysfunction of the intestinal epithelial barrier under elevated temperatures is assumed to prompt pathological conditions and to eventually impede chickens' growth, resulting in massive economic losses in broiler industries. The aims of this research were to determine the impact of acute heat stress on the intestinal tight junction network of broiler chicks (Gallus domesticus L.) and to elucidate whether adenosine monophosphate-activated protein kinase (AMPK) was involved in the integrated response of the broiler's gastrointestinal tract to heat stress. A total of 80 9-day-old Arbor Acres chicks were subjected to temperature treatment (thermoneutral versus heat stress) and AMPK inhibition treatment (5 mg/kg body weight intraperitoneal injection of compound C vs. sham treatment) for 72 h. In addition to monitoring growth performance, the mRNA and protein levels of key tight junction proteins, target components of the AMPK pathway, and biomarkers of intestinal inflammation and oxidative stress were assessed in the jejunum under both stressors at 24 and 72 h. An increase of the major tight junction proteins, claudin-1 and zonula occludens-1, was implemented in response to an exacerbated expression of the AMP-activated protein kinase. Heat stress did not affect zootechnical performance but was confirmed by an increased gene expression of heat shock proteins 70 and 90 as well as heat shock factor-1. In addition, hyperthermia induced significant effects on tight junction proteins, although it was independent of AMPK.