Kynurenic acid inhibits intestinal hypermotility and xanthine oxidase activity during experimental colon obstruction in dogs.

Kynurenic acid (KynA), an endogenous antagonist of N-methyl-d-aspartate (NMDA) glutamate receptors, protects the central nervous system in excitotoxic neurological diseases. We hypothesized that the inhibition of enteric glutamate receptors by KynA may influence dysmotility in the gastrointestinal tract. Group 1 of healthy dogs served as the sham-operated control, in group 2, the animals were treated with KynA, while in groups 3 and 4 mechanical colon obstruction was maintained for 7 h. Group 4 was treated with KynA at the onset of ileus. Hemodynamics and motility changes were monitored, and the activities of xanthine oxidoreductase (XOR) and myeloperoxidase (MPO) were determined from tissue samples. Colon obstruction induced a hyperdynamic circulatory reaction, significantly elevated the motility index and increased the mucosal leucocyte accumulation and the XOR activity. The KynA treatment augmented the tone of the colon, permanently decreased the motility index of the giant colonic contractions and reduced the increases in XOR and MPO activities. These effects were concomitant with the in vitro inhibition of XOR activity. In conclusion, KynA antagonizes the obstruction-induced motility responses and XOR activation in the colon. Inhibition of enteric NMDA receptors may provide an option to influence intestinal hypermotility and inflammatory changes.

Successful thoracoscopic surgical treatment of oesophageal cyst.

The authors report a video-thoracoscopically successfully treated case of oesophageal cyst. The symptomatic lesion was diagnosed by swallowing, X-ray, oesophagoscopy, chest CT scan and endoscopic ultrasonography. The benign tumour was removed by a videothoracoscopic method using selective intubation. There were no intraoperative and postoperative complications. The patient was discharged on the fifth postoperative day. The videothoracoscopic technique is safe, involves little pain and permits a rapid return to normal activity. It is a preferred method for removing benign lesions of the oesophagus.