The intestinal mucosa has the highest rate of turnover among tissues in young pigs. This rapid turnover makes enterocytes particularly vulnerable to chemo agents. L-Arginine plays an important role in intestinal physiology and has been studied as a component of an oral rehydration solution to enhance intestinal absorption and villous recovery after injury and has been shown to be effective in protecting against gastrointestinal injury. However, the underlying biochemical mechanisms are largely unknown. 

Recently, using procine enterocyte IPEC-1 model, researchers led by Academician YIN Yulong from Institute of Subtropical Agriculture, Chinese Academy of Sciences (ISA) conducted a study to determine the DNA synthesis and mitochondrial respiration by 5-ethynyl-2’-deoxyuridine (EdU) incorporation, flow cytometry analysis, extracellular flux analysis, etc. 

The researchers found that LPS induced mitochondrial dysfunction and cell-cycle impairment and arginine promoted DNA synthesis and mitochondrial bioenergetics in intestinal epithelial cells. Possible mechanisms for the cytoprotective effect of arginine are proposed that arginine stimulated PI3K and Akt phosphorylation, thereby inhibiting Bcl2 and ameliorating cell-cycle arrest and apoptosis brought about by an endotoxin. These findings provide a biochemical basis for dietary arginine supplementation to improve the regeneration and repair of the small-intestinal mucosa in both animals and humans. 

This research was jointly supported by the National Natural Science Foundation of China (No. 31330075, 31372326, 31301989, and 31272450), National Key Basic Research Program of China (2013CB127301 and 2012CB126305), and Texas A&M AgriLife Research (H-8200). 

The findings were published recently in Frontiers in Bioscience, Landmark.