人脐血造血干/祖细胞对裸鼠的致突变作用

目的研究人脐血造血干/祖细胞(HS/PCs-HUCB)对裸鼠的致突变作用。方法取雄性BALB/c裸鼠,随机分为5组:HS/PCs-HUCB高、中、低剂量组及阴性、阳性对照组,HS/PCs-HUCB高、中、低剂量组分别经尾静脉注射1.25×109、3.75×108和1.25×108个细胞/kg,阴性对照组经尾静脉注射含1%人血白蛋白的0.9%NaCl注射液,50ml/kg,阳性对照组经腹腔注射环磷酰胺,50mg/kg,每d给药1次。微核试验连续给药2d,末次给药24h后取骨髓细胞涂片,Giemsa染色,每组裸鼠计数12000个骨髓嗜多染红细胞(PCE)中微核细胞数;精子畸形试验连续给药5d,首次给药后第35天取附睾,精子滴片,伊红染色,每组裸鼠计数1500个精子的形态。结果HS/PCs-HUCB各剂量组裸鼠的微核率和精子畸形率与阴性对照组比较,差异均无统计学意义,各组间精子畸形类型构成比差异无统计学意义,畸形精子以无定形为主,其次为无钩、双头、双尾、双体、胖头等;而阳性对照组的微核率和精子畸形率均显著高于阴性对照组。结论HS/PCs-HUCB对裸鼠无致突变作用。

Mutagenic Action of Hematopoietic Stem/Progenitor Cells from Human Umbilical Cord Blood in Nude Mice

Objective To study the mutagenic action of hematopoietic stem / progenitor cells from human umbilical cord blood(HS / PCs-HUCB)in nude mice. Methods Male BALB / c nude mice were divided into three test, one negative control and one positive control groups randomly. The mice in three test groups were injected i.v. with HS / PCs-HUCB at dosages of 1. 25 × 109, 3. 75 × 108 and 1. 25 × 108 cells / kg respectively, while those in negative control group with 0.9% sodium chloride injection containing 1% human serum albumin at a dosage of 50 ml / kg. However, the mice in positive control group were injected i.p. with cyclophosphamide at a dosage of 50 mg / kg. The mice for micronucleus test were injected once a day for 2 d, and their bone marrow cells were smeared and stained with Giemsa 24 h after the last injection, based on which the micronucleated cells in every 12 000 polychromatic erythrocytes(PCE)in bone marrow of mice in each group were counted. However, the mice for sperm abnormality test were injected once a day for 5 d, and their epididymides were isolated on day 35 after the first injection for preparation of sperm smear which was stained with eosin, and the morphologies of 1 500 sperms of mice in each group were observed. Results The micronucleus and sperm abnormality rates of nude mice in the three test groups showed no significant difference with those in negative control group. The ratios of various types of teratosperms in various groups showed no significant difference. In the turn of number, the teratosperms were those with amorphous heads, without hooks, with double heads, with double tails, with double heads and with big heads. However, both micronucleus and sperm abnormality rates in positive control group were significantly higher than those in negative control group. Conclusion HS / PCs-HUCB showed no mutagenic action on nude mice.