1. Collect ascites
Fix the animal in a natural standing position. The puncture site is on both sides of the midline of the abdomen, between the front edge of the pubic bone and the umbilical cord. Shedding, disinfection, local infiltration anesthesia. The operator's left thumb and index finger tighten the skin at the puncture site, and the right hand controls the puncture depth of the vertical puncture. Be careful not to pierce the internal organs and do not pierce deep. After the puncture needle enters the abdomen, the abdominal pressure is very high, so it can be seen that the abdominal water will drain automatically for a long time. If you have very little ascites, retract gently while turning the needle slightly. As soon as the ascites comes out, fix the position of the needle and syringe and continue to suck. When pumping the abdominal pressure, please be careful not to pump too fast, do not pump a large amount of ascites at a time, so as to avoid problems such as animal circulatory dysfunction due to a sudden drop in abdominal pressure.
2, saliva collection
In an acute experiment, a straw can be inserted directly into the animal’s mouth or saliva tube to suck out saliva. The method is very simple, but the saliva inhaled through the mouth is mixed with impurities.
3. Collect gastric juice
1. To collect gastric juice directly for acute experiments, the animals can be anesthetized first, and for dogs, gastric juice can be collected by gastrointestinal methods. For rats, abdominal surgery is required. A plastic tube is inserted into the stomach through the mouth, and then the mouth is passed through the esophagus. Insert the plastic tube into the front stomach, and forcibly inject normal saline with pH 7.0 and about 35°C at a flow rate of 12 ml/h, and collect and analyze the effluent.
2. Preparation of gastrostomy methods In chronic experiments, gastrostomy methods such as total gastrostomy, Pap small gastrostomy and high small gastrostomy are usually used to collect gastric juice. The preparation of the small stomach is to separate and connect a small part of the animal's stomach to form the small stomach. The main stomach and the small stomach are not connected to each other. The main stomach digests normally and can collect pure gastric juice from the small stomach. This method allows repeated collection of gastric juice while the animal is awake after recovering health.