Microarray analysis of gene expression profiles of rat small intestine in response to heat stress.

Ambient temperature is a critical factor that affects biological organisms in many ways. In this study, the authors investigated gene expression changes in rat small intestine in response to heat stress. Male Sprague-Dawley rats were randomly divided into control and heat-stressed groups. Both groups were housed at 25 °C, although the heat-stressed group was also subjected to 40 °C for 2 h each day for 10 successive days. Rats were sacrificed 1, 3, 6, and 10 days after heat treatment, and sections of their small intestine epithelial tissue were excised for morphological examination and microarray analyses. The rat rectal and body surface temperatures and serum cortisol levels were all significantly increased after heat treatment (p < 0.05). The jejuna were significantly damaged by 3 days after heat treatment began. Microarray analysis showed that 422 genes were differentially expressed, of which 290 genes were significantly upregulated and 132 genes were significantly downregulated. Subsequent bioinformatics analyses revealed that the differentially expressed genes were mainly related to stress, immune regulation, and metabolism processes. The bioinformatics analysis of the differentially expressed genes should be beneficial to further investigations on the underlying mechanisms involved in heat stress-induced damage in the small intestine.