Effects of interleukin-6 in hypothalamus on gastric mucosal injury in rats with stress ulcer

Objective To clarify the role of hypothalamic IL-6 in gastric mucosal blood flow, gastric juice pH value and gastric mucosal injury. Method Model of gastric stress ulcer was established by fluid percussion to make craniocerebral trauma. Twenty male SD rats fed for one week in the experiment room were randomly(random number) divided into control group, one hour group, six hours group and 12 hours group after injury. The levels and distribution of IL-6 in hypothalamus were detected by using immunohistochemistry and Western blot. Simultaneously, gastric pH value, gastric mucosal blood flow and gastric mucosal injury index of rats in each group were measured, and the histology of gastric mucosa was observed. Results IL-6 immunoreactive cells were widely distributed in neuronal cells of hypothalamus of the stressed rats especially in the para-ventricular nucleus (PVN).One hour after injury, the pH value rapidly declined, and the lowest point appeared 6 hours later. One hour after injury, the injury of gastric mucosa was found, and the injury became worse and worse as time got longer and longer. The ulcer index (UI) was increased. One hour after injury, there was a brief increase in blood flow to the peak in gastric mucosa, and then the blood flow declined until 6 hours elapsed and got stable. The experiment prompted the gastric stress ulcer appeared. Conclusions In the SD rats with gastric stress ulcer induced by craniocerebral injury incurred by hydraulic percussion, the hypothalamic IL-6 may activate neuronendocrine metabolism mediated through the activation of PVN, inducing gastric mucosal injury. Key words: Brain injury;  Fluid-percussion model;  Rat;  Immunohistochemistry;  IL-6;  Stress ulcer