Neutrophil-derived hydroxyl radicals mediate interleukin-8-induced increases in tetragastrin-stimulated acid secretion in rats.

Until recently, the secretion of gastric acid, which plays an important role in the pathogenesis of peptic ulcer, was thought to be controlled by diet, the autonomic nerves and gut hormones. However, peptic ulcer is now known to be caused by the infection with Helicobacter pylori (H. pylori), so it is possible that inflammation modifies the secretion of gastric acid. We used gastric-lumen-perfused rats to first examine the effect of interleukin-8 (IL-8) on acid secretion and then the involvement of free radicals and neutrophils in the action of IL-8. IL-8 enhanced tetragastrin-stimulated acid secretion and free radical scavengers or inhibitors and the pretreatment with anti-rat neutrophil serum inhibited this effect, which indicates that IL-8 enhances gastrin-stimulated acid secretion and that neutrophil-derived hydroxyl radicals mediate the IL-8-induced increase in acid secretion.

Superior mesenteric arterial embolism: treatment by trans-catheter thrombo-aspiration.

A 57-year-old woman with hypertension, mixed mitral valve disease, and atrial fibrillation was admitted to our hospital because of abdominal pain continuing for several hours. On the following day, colonoscopy was performed, and diffuse yellow-white pseudomembranous changes were seen in the right hemicolon, but there were no abnormal findings in the left hemicolon; 24 h after onset, a diagnosis of superior mesenteric arterial embolism was made on the computed tomography (CT) scan findings. Abdominal angiography was performed and showed complete occlusion of the superior mesenteric artery (SMA). Then conservative treatment, using per-catheteric thrombus aspiration, was done, followed by intraarterial injection of tissue type plasminogen activator. After the thrombo-aspiration, the filling deficit of the main artery had disappeared, and the branches on the right side were clearly delineated. After the treatment, the symptoms such as abdominal pain and diarrhea improved accordingly. She was discharged from the hospital 27 days later. Our case suggests that trans-catheter thrombo-aspiration is a possible alternative to open embolectomy for some cases of SMA embolism more than 10 h post-onset.

[The treatment of peptic ulcer in elderly CRF patients].

It is well known that CRF patients may suffer from various types of upper GI tract lesions such as esophagitis, erosive or atrophic gastritis, gastro-duodenal ulcers and polyps. Above all, acute gastric mucosal lesion with atrophic changes has been complicated with elderly CRF patients in relatively high frequency in recent years. A number of causes for upper GI tract lesions in CRF patients have been raised, which include mental and physical stresses, hypergastrinemia associated with lower renal metabolic clearance rate, secondary hyperparathyroidism, hypoperfusion in gastric mucosal blood flow, malnutrition, and also H. pylori recently. The treatments for these upper GI tract lesions are directed toward both suppression of offensive factors and strengthening of defensive factors in gastro-duodenal mucosae. It is needless to say that special attentions should be always paid for doses, intervals or durations in any drugs prescribed for elderly CRF patients because of lower renal metabolic clearance rates for drugs.

Neuronal expression of Fos protein in the brain after intravenous injection of gastrin in rats.

The present study examined whether the central neurons are involved in the stimulatory action of gastrin on the secretion of gastric acid. Gastrin (20 microg), which was examined and ascertained to induce a marked increase in gastric acid secretion in gastric-lumen perfused rats, was intravenously injected in Wistar rats under anesthesia with pentobarbital sodium. In the experiments, 1 h after injecting gastrin, rats were perfused and fixed, the brain was removed and sectioned at 40 microm thickness. Every fourth section was treated with anti-c-Fos antiserum, and c-Fos protein was immunohistochemically stained using the avidin-biotin complex method. It was found that c-Fos protein was expressed in neurons of the lateral habenular nucleus, the central nucleus amygdala, the lateral parabrachial nucleus in the pons, and the complex area of the nucleus of the solitary tract and the dorsal motor nucleus of the vagus nerve in the medulla oblongata. The control rats were injected with saline solution, and the brain sections were processed similarly as described above. c-Fos protein was expressed in few neurons in the nuclei above in the control rats. These results suggest that gastrin released into the circulation might stimulate central neurons which, in turn, may relate to the control mechanism for the secretion of gastric acid.