Tsuyoshi T, Takeuchi M, Hirono H, Masamoto Y
Research Department, Sunstar Inc., Osaka, Japan.
Mutat Res. 1989 Aug;223(4):383-6. doi: 10.1016/0165-1218(89)90091-8.
The effects of 2 routes of administration, intraperitoneal injection (i.p.) and oral gavage (p.o.), in the micronucleus test were evaluated using methyl methanesulfonate (MMS) and 2 strains of mice (MS/Ae and CD-1). A small-scale acute toxicity study and a pilot micronucleus experiment were carried out first. On the basis of the results obtained, a final micronucleus test was performed at doses of 20, 40, 80, and 160 mg/kg (i.p.) and 40, 80, 160, and 320 mg/kg (p.o.), with a 24-h sampling time. MMS induced micronucleated polychromatic erythrocytes (MNPCEs) in both routes in both mouse strains under the conditions used. At 40 and 80 mg/kg, MMS induced a higher number of MNPCEs by the i.p. route in both strains. A 160 mg/kg MMS dose induced higher numbers of MNPCEs by the p.o. route in MS/Ae mice. The route-related difference with MMS on the basis of mg/kg disappeared when the difference was determined on the basis of a ratio of the LD50. In practice, both i.p. and p.o. routes are acceptable as routes of administration in the micronucleus test using this chemical.
使用甲磺酸甲酯（MMS）和两种小鼠品系（MS/Ae和CD-1）评估了腹腔注射（i.p.）和灌胃（p.o.）两种给药途径在微核试验中的效果。首先进行了小规模急性毒性研究和预试验微核实验。根据所得结果，在20、40、80和160 mg/kg（腹腔注射）以及40、80、160和320 mg/kg（灌胃）的剂量下进行了最终微核试验，采样时间为24小时。在所使用的条件下，MMS在两种小鼠品系的两种给药途径中均诱导产生了微核多染红细胞（MNPCEs）。在40和80 mg/kg剂量下，MMS通过腹腔注射途径在两种品系中诱导产生的MNPCEs数量更多。160 mg/kg的MMS剂量通过灌胃途径在MS/Ae小鼠中诱导产生了更多的MNPCEs。当基于半数致死剂量（LD50）的比例来确定差异时，基于mg/kg的MMS与给药途径相关的差异消失了。实际上，在使用这种化学物质的微核试验中，腹腔注射和灌胃这两种给药途径都是可以接受的。
