4-Ethoxymethylene-2-phenyl-2-oxazolin-5-one

Colitis induction^[1]
1.Prepare procedure
Preparation of sensitization solution (I):
Mix acetone and olive oil in a 4:1 v/v ratio by vortexing. Dissolve a 60 mg oxazolone in 2 mL of this solution to obtain a 3 % (w/v) oxazolone sensitization solution. Mix the solution by carefully vortexing.
Preparation of challenge solution (II):
Dissolve 20 mg Oxazolone in 2 mL of 50 % ethanol to obtain a 1 % (w/v) solution. Mix the solution by careful vortexing. The oxazolone powder should be completely dissolved before use.

2. Experimental procedure
Sensitization pretreatment:
The electric scissors scraped an area of about 2 cmx2 cm on the skin of the mice's backs. Be careful to avoid open wounds.
Apply 150 μL of sensitizing solution (working solution 1) to the exposed skin of mice. Be careful to use an Oxazolone-free sensitizer as a control. Induction treatment:
Anesthetized mice: intraperitoneally injected ketamine/thiazide solution (80 μL/10 g), or inhaled with isoflurane anesthesia system.
The catheter was inserted into the colon of the mice (about 3-4 cm deep at the proximal end of the anus). The other end of the catheter is connected to a 1 mL syringe.
About 100 μL of oxazolone stimulation solution is injected into the colonic cavity through a catheter for 10 to 30 seconds. After dosing, hold the mouse in a vertical position (head down) for 60 seconds.