Methods:LES pressure was determined in 20 dogs. BTA was endoscopically injected circumferentially into the LES in 10 dogs, and saline injection as control group(10 dogs).

• 方法：在胃镜下对BTA组（10条犬）LES分四点注射BTA，对照组（10条犬）注射生理盐水，分别于注射前?注射后一周测定LES的压力。