不同胎次小鼠的异氟醚吸入麻醉效价

Isoflurane Potency in Mice from the First and Second Parity

目的比较挥发麻醉药在不同胎次小鼠的麻醉效价。方法选择24只SPF级封闭群ICR/CD-1小鼠,雌雄各半,按1:1比例交配。生产第1胎和第2胎,形成祖代相同的两个胎次子代小鼠。观察并记录小鼠的繁殖和生长情况,包括每胎产仔数、产仔性别比例、仔鼠死亡率以及小鼠在不同生长阶段的体质量。待仔鼠成长至65～75日龄时,以翻正反射消失为判断麻醉的终点指标,应用续贯法测定异氟醚在两个胎次小鼠中的吸入麻醉半数有效浓度。结果两个胎次分别获得104和109只小鼠,并进行了异氟醚半数有效浓度的测定。小鼠繁殖情况在两胎间差异无统计学意义(P>0.05)。两胎小鼠的体质量,在相同发育阶段差异无统计学意义,但雄性小鼠体质量在离乳和半数有效浓度测定时明显大于雌性(P<0.05)。异氟醚吸入麻醉半数有效浓度在两胎间和不同性别间差异无统计学意义(P>0.05)。结论胎次对挥发麻醉药在小鼠麻醉时的效价无显著影响。

Objective To determine the influence of parity on the potency of volatile anesthetics in mice. Methods 24 ICR/CD- 1 mice（ half male and half female） mated one another to compose 12 pairs of parents. Each pair was allowed to produce two succeeding litters. Reproductive characteristics were observed and documented, including litter size at birth, sex ratio at weaning, and neonatal mortality. Body weight was measured at birth, at the time of weaning, and at the time of anesthetic potency determination. At 65 - 75 days of age, median effective concentration （ EC50 ） of inhaled isoflurane was measured in mice from the two parities by using a bracketing design. Loss of righting reflex was chosen as the successful induction of anesthesia. Results 104 and 109 offspring were obtained in the two parities for the determination of isoflurane EC50. There were no significant differences of reproductive characteristics and body weight across the two parities（ P 〉 0.05 ）. Males were heavier than females at weaning and at ECs0 determination （ P 〈 0.05 ）. No significant differences were found in isoflurane EC50 across the parity, and across the sex within parity. Conclusion Volatile anesthetic potency was identical in mice from two succeeding parities.