Published online Jul 7, 2017. doi: 10.3748/wjg.v23.i25.4529
Peer-review started: February 9, 2017
First decision: February 23, 2017
Revised: March 3, 2017
Accepted: June 12, 2017
Article in press: June 12, 2017
Published online: July 7, 2017
Processing time: 154 Days and 13.1 Hours
To evaluate the protective effects of glutamine in a model of portal hypertension (PH) induced by partial portal vein ligation (PPVL).
Male Wistar rats were housed in a controlled environment and were allowed access to food and water ad libitum. Twenty-four male Wistar rats were divided into four experimental groups: (1) control group (SO) - rats underwent exploratory laparotomy; (2) control + glutamine group (SO + G) - rats were subjected to laparotomy and were treated intraperitoneally with glutamine; (3) portal hypertension group (PPVL) - rats were subjected to PPVL; and (4) PPVL + glutamine group (PPVL + G) - rats were treated intraperitoneally with glutamine for seven days. Local injuries were determined by evaluating intestinal segments for oxidative stress using lipid peroxidation and the activities of glutathione peroxidase (GPx), endothelial nitric oxide synthase (eNOS) and inducible nitric oxide synthase (iNOS) after PPVL.
Lipid peroxidation of the membrane was increased in the animals subjected to PH (P < 0.01). However, the group that received glutamine for seven days after the PPVL procedure showed levels of lipid peroxidation similar to those of the control groups (P > 0.05). The activity of the antioxidant enzyme GTx was decreased in the gut of animals subjected to PH compared with that in the control group of animals not subjected to PH (P < 0.01). However, the group that received glutamine for seven days after the PPVL showed similar GTx activity to both the control groups not subjected to PH (P > 0.05). At least 10 random, non-overlapping images of each histological slide with 200 × magnification (44 pixel = 1 μm) were captured. The sum means of all areas, of each group were calculated. The mean areas of eNOS staining for both of the control groups were similar. The PPVL group showed the largest area of staining for eNOS. The PPVL + G group had the second highest amount of staining, but the mean value was much lower than that of the PPVL group (P < 0.01). For iNOS, the control (SO) and control + G (SO + G) groups showed similar areas of staining. The PPVL group contained the largest area of iNOS staining, followed by the PPVL + G group; however, this area was significantly smaller than that of the group that underwent PH without glutamine (P < 0.01).
Treatment with glutamine prevents gut mucosal injury after PH in rats.
Core tip: Portal hypertension (PH) is characterized by an increased portal pressure gradient. The progressive increase in portal pressure leads to the formation of portosystemic shunts and intestinal hypoxia. Many enzymes have been implicated in this process, among them endothelial nitric oxide synthase and inducible nitric oxide synthase. Some substances, such as glutamine, have been studied as protective agents against oxidative stress. In an experimental model of PH induced by partial portal vein ligation, we have found that glutamine reduced lipid peroxidation and preserved intestinal glutathione peroxidase activity, suggesting a protective role of this amino acid in the setting of PH.