[Effect of Y-25130 on gastric motility in anesthetized rats]

We developed an automatic analyzing system using a personal computer to evaluate gastric motility objectively. Gastric motility was divided into three elements: motility index, amplitude and frequency. These elements analyzed with both computer and manual methods closely correlated with each other (R2 = 0.943, 0.985 and 0.986, respectively). The effect of Y-25130 on gastric motility was investigated in anesthetized rats with the automatic analyzing system. Intravenous administration of Y-25130 increased both spontaneous and cisplatin-reduced gastric motility. The effect of Y-25130 on spontaneous motility was superior to that of ondansetron and metoclopramide, and the effect on cisplatin-reduced motility was almost the same as that of ondansetron and superior to that of metoclopramide. In vagotomized rats, Y-25130 did not increase the gastric motility not only in spontaneous conditions but also in efferent vagus stimulated conditions. Atropine completely blocked the gastric motility induced by Y-25130. In capsaicin pre-treated rats, Y-25130 had no effect. On the other hand, Y-25130 increased the gastric motility induced by afferent vagus stimulation. These results suggest that Y-25130 increases gastric motility through the vagus nerve and acts on afferent neurons.