Effects of Hydrogen Peroxide-Induced Oxidative Stress on Intestinal Morphology, Redox Status, and Related Molecules in Squabs

SIMPLE SUMMARY: Oxidative stress is a detrimental physiological state, which can adversely affect both the health and productivity of poultry, therefore strategies to identify its underlying regulatory mechanisms are crucial for poultry science. However, mechanisms contributing to oxidative stress in pigeons have not been investigated in detail previously. Therefore, we established a squab intestinal oxidative stress model, observed the changes in intestinal morphology, and detected the changes in the content of oxidative stress markers and the relative RNA expression of related genes to explore the possible mechanism of oxidative stress in the intestine of squab. The results showed that intestinal oxidative stress could lead to weight loss, intestinal morphology changes, autophagy, and apoptosis in the squabs intestine. ABSTRACT: The purpose of this study was to evaluate the potential effect of oxidative stress on the intestine of squabs, and to explore the molecular mechanisms. A total of 360 1-day-old squabs were divided evenly into five different groups (n = 72/group): control, negative control, low, medium, and high dose groups. On the 3rd, 5th, and 7th days, squabs in the control group were not effectively treated and the negative control group were intraperitoneally injected with normal saline, whereas the H(2)O(2) group was injected with H(2)O(2) of 2.0, 2.5, and 3.0 mmol/kg BW respectively. On the 21st day, the serum and duodenum were collected for further analysis. The results indicated that, compared with the control group, H(2)O(2) caused squabs weight loss and intestinal morphology damage, and these effects were enhanced with an increase in dose. Further examination revealed that the contents of oxidative stress markers in both the serum and duodenum of the H(2)O(2) group were significantly enhanced as the dose was increased. In addition, H(2)O(2) exposure also resulted in the lower mRNA expression of Occludin, ZO-1, Beclin1, Atg5, and Caspase-3, but the expression of Claudin2 and Bcl-2 was decreased in comparison to the control group. These findings suggested that duodenal oxidative damage was accompanied by weight loss, changes in intestinal morphology, redox status imbalance, apoptosis as well as autophagy of intestinal cells, with, effects of 3.0 mmol/kg BW of H(2)O(2) being the most severe.