Objective To improve the preparation of trachea spiral strips of guinea pigs by spiral cutting using surgical scissors and to establish a new method of spiral cutting using surgical blade.MethodsForty guinea pigs were enrolled in this experiment. By method of spiral cutting with surgical scissor or surgical blade to prepare isolated guinea pig trachea spiral strips, and incubate them in Kreb''s solution for 2 hours. Contraction of the trachea spiral strips were induced by histamine in concentration of 2.0×10-3 g/L or acetylcholine in concentration of 2.0×10-4 g/L. The changes of tension values were measured using a BL420 biological signal acquisition system and tension sensors. SPSS 11.5 software was used to analyze the data (t test, α=0.05). ResultsUnder 2 g tension, the contraction caused by histamine of the surgical blade-prepared trachea strips was 1.31-fold higher than that of surgical scissors-prepared tracheal strips, and the contraction caused by acetylcholine of the surgical blade-prepared trachea strips was 1.208-fold higher than that of surgical scissors-prepared tracheal strips, both with a significant difference (t test, P<0.05). The contraction amplitude caused by histamine of surgical blade-prepared specimens under 2 g tension was 1.48-fold higher than that caused under 1 g tension, and the contraction amplitude of that caused by acetylcholine under 2 g tension was 1.38-fold higher than that under 1 g tension, both with a significant difference (t test, P<0.05). When histamine and acetylcholine were washed out from the tracheal strips, their tension returned to baseline. The RSD values of contraction amplitude of surgical blade-prepared strips were 19.8% (by histamine) and 19.1% (by acetylcholine), and the RSD values of contraction amplitude of surgical scissors-prepared strips were 35.3% (by histamine) and 33.7%. ConclusionsComparing the surgical blade-prepared tracheal spiral strips with those of surgical scissors-prepared ones, the former is more sensitive to histamine and acetylcholine treatment, and it is better to be treated under 2 g tension. The contraction variation caused by recycling of surgical blade-prepared specimens is smaller than that of surgical scissors-prepared specimens.