Schatten H, Chakrabarti A
Department of Veterinary Pathobiology, University of Missouri-Columbia 65211, USA.
Eur J Cell Biol. 1998 Jan;75(1):9-20. doi: 10.1016/S0171-9335(98)80041-1.
This paper explores the mode of action of the tranquillizers chloral hydrate and diazepam during fertilization and mitosis of the first reproductive cell cycles in sea urchin eggs. Most striking effects of these drugs are the alteration of centrosomal material and the abnormal microtubule configurations during exposure and after recovery from the drugs. This finding is utilized to study the mechanisms of centrosome compaction and decompaction and the dynamic configurational changes of centrosomal material and its interactions with microtubules. When 0.1% chloral hydrate or 350-750 microM diazepam is applied at specific phases during the first cell cycle of sea urchin eggs, expanded centrosomal material compacts at distinct regions and super-compacts into dense spheres while microtubules disassemble. When eggs are treated before pronuclear fusion, centrosomal material aggregates around each of the two pronuclei while microtubules disappear. Upon recovery, atypical asters oftentimes with multiple foci are formed from centrosomal material surrounding the pronuclei which indicates that the drugs have affected centrosomal material and prevent it from functioning normally. Electron microscopy and immunofluorescence studies with antibodies that routinely stain centrosomes in sea urchin eggs (4D2; and Ah-6) depict centrosomal material that is altered when compared to control cells. This centrosomal material is not able to reform normal microtubule patterns upon recovery but will form multiple asters around the two pronuclei. When cells are treated with 0.1% chloral hydrate or 350-750 microM diazepam during mitosis, the bipolar centrosomal material becomes compacted and aggregates into multiple dense spheres while spindle and polar microtubules disassemble. With increased incubation time, the smaller dense centrosome particles aggregate into bigger and fewer spheres. Upon recovery, unusual irregular microtubule configurations are formed from centrosomes that have lost their ability to reform normal mitotic figures. These results indicate that chloral hydrate and diazepam affect centrosome structure which results in the inability to reform normal microtubule formations and causes abnormal fertilization and mitosis.
本文探讨了镇静剂水合氯醛和地西泮在海胆卵首次生殖细胞周期的受精和有丝分裂过程中的作用模式。这些药物最显著的作用是在暴露期间和从药物中恢复后，中心体物质发生改变以及微管构型异常。这一发现被用于研究中心体压缩和解压缩的机制以及中心体物质的动态构型变化及其与微管的相互作用。当在海胆卵的第一个细胞周期的特定阶段应用0.1%的水合氯醛或350 - 750微摩尔的地西泮时，扩展的中心体物质在不同区域压缩并超压缩成致密球体，同时微管解体。当卵子在原核融合前处理时，中心体物质聚集在两个原核周围，而微管消失。恢复后，通常由围绕原核的中心体物质形成具有多个焦点的非典型星体，这表明药物影响了中心体物质并阻止其正常发挥功能。用常规染色海胆卵中心体的抗体（4D2和Ah - 6）进行的电子显微镜和免疫荧光研究表明，与对照细胞相比，中心体物质发生了改变。这种中心体物质在恢复后无法重新形成正常的微管模式，但会在两个原核周围形成多个星体。当细胞在有丝分裂期间用0.1%的水合氯醛或350 - 750微摩尔的地西泮处理时，双极中心体物质被压缩并聚集成多个致密球体，而纺锤体和极微管解体。随着孵育时间的增加，较小的致密中心体颗粒聚集成更大且更少的球体。恢复后，由失去重新形成正常有丝分裂形态能力的中心体形成异常不规则的微管构型。这些结果表明，水合氯醛和地西泮影响中心体结构，导致无法重新形成正常的微管结构，并引起异常受精和有丝分裂。
