The duodenum absorbs nearly all secreted gastric acid. Carbonic anhydrases facilitate transmucosal acid movement. The upper gastrointestinal tract must resist a variety of injuries, including those caused by ingested noxious substances, acid, ischemia/reperfusion, and infections such as Helicobacter pylori. The results are similar, however, regardless of insult: inflammation, ulceration, or metaplasia/dysplasia. In the past year, there have been prominent findings suggesting that oxidative stress and the formation of reactive oxygen species may play a pivotal role in all forms of injury, and that antioxidants may be the key to injury prevention and healing.
Oxidative injury may be a common mechanism by which the upper gastrointestinal mucosa responds to noxious insults. Endogenous antioxidants, such as ghrelin, L-carnitine, and annexin-1 attenuate the oxidative-stress response. Similarly, exogenous antioxidants have also been shown to decrease inflammation, upregulate free radical scavengers, and prevent the formation of reactive oxygen species.
Many studies published in the past year have linked oxidative stress to a variety of upper gastrointestinal insults. Exogenous and endogenous antioxidant compounds prevent the oxidative stress response. The future holds great promise for the development of pharmaceuticals with antioxidant properties that are safe, efficacious, and inexpensive.
aGreater Los Angeles Veteran Affairs Healthcare System, WLAVA Medical Center, USA
bDepartment of Internal Medicine, UCLA Medical Center, USA
cCURE: Digestive Diseases Research Center Department of Medicine, UCLA School of Medicine, USA
dBrentwood Biomedical Research Institute, Los Angeles, California, USA
Correspondence to Jonathan D. Kaunitz, MD, Building 114, Suite 217, West Los Angeles VAMC, Los Angeles, CA 90073, USA Tel: +1 310 268 3879; fax: +1 310 268 4811; e-mail: email@example.com