Endothelin-1 in the gastric mucosa in stress ulcers of critically ill patients

Objective: Gastric microcirculatory disturbances are involved in the pathogenesis of stress ulcers; however, vasomodulators causing this process are not fully understood. This study was conducted to investigate the role of endothelin 1 (ET-1), a potent vasoconstrictive peptide, in stress ulcers in critically ill patients. Methods: Using sandwich enzyme immunoassay, we measured ET-1 content in plasma and the gastric mucosa of 16 critically ill patients with traumatic head injury on admission and of 11 healthy subjects. Gastric mucosal samples were obtained endoscopically. When gastric drainage contained occult blood, endoscopic examination was performed again, and ET-1 concentrations in injured and adjacent normal mucosa were compared. Results: Plasma and mucosal ET-I concentrations were significantly higher in critically ill patients on admission (6,1 0.6 μg/ml and 13.8 ± 1.6 ng/g, respectively) compared with values in control subjects (2.7 0.4 pglml and 8.2 ± 0.5 nglg, respectively) (p < 0.01). The mucosal ET-1 concentration tended to be elevated in patients who had experienced hypoxia compared with those who had not (p = 0.07). In five patients who were again examined endoscopically, the ET-1 concentration in the injured mucosa was significantly higher than that in adjacent mucosa (19.2 3.2 and 10.1 ± 1.6 ng/g, respectively; p < 0.05). Conclusions: These results suggest that endogenous ET-1 plays an important role in the local pathogenesis of stress ulcers, especially those caused by hypoxia.