Kallio M, Sjöblom T, Lähdetie J
Department of Medical Genetics, University of Turku, Finland.
Environ Mol Mutagen. 1995;25(2):106-17. doi: 10.1002/em.2850250204.
We have studied the effects of vinblastine sulfate (VBL) and colchicine (COL) on male rat in vivo and in vitro meiosis. A novel methodology based on isolating a segment of seminiferous tubules containing meiotically dividing spermatocytes was applied. During meiotic divisions at stage XIV of rat spermatogenesis, both chemicals induced only low frequencies of micronuclei (MN), 0.8-3.2 MN/1,000 spermatids. Fluorescence in situ hybridization experiments in mice with the mouse centromere-specific gamma-satellite DNA probe showed that 50.7% of VBL-induced MN and 56.6% of COL-induced MN were centromere positive, indicating that the MN induced by both chemicals contained detached chromosomes. The inhibition of cell proliferation was determined by counting the number of cells arrested at metaphase during the first meiotic (MI) or the second meiotic (MII) division. VBL was found to be a potent inducer of cell death while COL was not. The direct effects of VBL and COL on the meiotic spindles were evaluated using immunohistochemistry with anti-alpha-tubulin and confocal microscopy. In the control animals a significant difference was observed between the mean length of metaphase spindles of MI and MII. Both were dramatically decreased 6 hr after treatment with 2.0 mg/kg of VBL and 0.8 mg/kg of COL, respectively. At 18 hr after COL injection the spindles had about the same length as in the controls. However, the VBL-induced shortening was even more evident at 18 hr for both MI and MII. The possible reasons for observed differences between the two chemicals and between meiosis and mitosis are discussed.
我们研究了硫酸长春碱（VBL）和秋水仙碱（COL）对雄性大鼠体内和体外减数分裂的影响。应用了一种基于分离一段含有进行减数分裂的精母细胞的生精小管的新方法。在大鼠精子发生的第十四阶段减数分裂期间，两种化学物质仅诱导出低频率的微核（MN），每1000个精子细胞中有0.8 - 3.2个微核。用小鼠着丝粒特异性γ卫星DNA探针在小鼠中进行的荧光原位杂交实验表明，50.7%的VBL诱导的微核和56.6%的COL诱导的微核着丝粒呈阳性，表明这两种化学物质诱导的微核都含有分离的染色体。通过计算在第一次减数分裂（MI）或第二次减数分裂（MII）期间停滞在中期的细胞数量来确定细胞增殖的抑制情况。发现VBL是一种有效的细胞死亡诱导剂，而COL不是。使用抗α微管蛋白免疫组织化学和共聚焦显微镜评估了VBL和COL对减数分裂纺锤体的直接影响。在对照动物中，观察到MI和MII中期纺锤体的平均长度存在显著差异。在用2.0 mg/kg的VBL和0.8 mg/kg的COL处理6小时后，两者均显著缩短。在注射COL后18小时，纺锤体长度与对照中的大致相同。然而，对于MI和MII，VBL诱导的缩短在18小时时更为明显。讨论了观察到的两种化学物质之间以及减数分裂和有丝分裂之间差异的可能原因。
