Effect of botulinum toxin-A on gastric emptying and gastrointestinal hormone

Objective To study the effect of Botulinum Toxin-A on the gastric emptying and gastrointestinal hormone.Methods Male wistar rats were divided into four groups: small dose group, middle dose group, large dose group and control group. Each rat was laparotomized injected BTA solution 0.4ml or saline 0.4ml in antrum. At the twelveth weekend, gastric semi-empty time was determined by nuclide scan and the contents of CCK、VIP and motilin in antrum was measured by immunohistochemistry method and radio-immunity method.Results At the twelveth weekend, gastric semi-empty time in middle dose group (161.67±23.53 min) and large dose group(200.33±44.37 min) were significantly longer than those in control group(86.83±22.98 min),(P0.05). Plasm motilin in middle dose group(80.56±10.43 pg/ml) and large dose group (65.99±10.50 pg/ml) were significantly lower than those in control group (123.65±31.10 pg/ml),(P 0.05 ). The results of immunohistochemistry revealed that IOD of the CCK expressed in antrum myenteric plexus in large dose group (139.83±37.39) were much higher than those in control group(77.91±32.21),(P0.05). IOD of VIP positive-staining in antrum myenteric plexus in middle dose group ( 63.83±19.62) and in large dose group (58.40±15.52) were much lower than those in control group (100.04±26.36),(P0.05). Conclusion BTA injected in antrum smooth muscle in rats can reduce gastric empty, The changes of MTL、VIP and CCK may be associated with the decrease of gastric empty induced by BTA. These findings offer a new clue for exploring the fresh mechanism of BTA.