Mechanism of Colchicine-Mitosis 



401 



indifferent poisons, and that their influence on mitosis was quite 

 similar to the changes brought aljout in the nervous system l)y the 

 so-called indiftcrent narcotics. Physical changes appeared prominent, 

 and c-miiosis was called a "narcoti/ed" mitosis. The suljstances listed 

 as not following the rule included aniline, phenol, hexanilrodipheji- 

 ylduinir. and coUhiciue. The activity of phenol and aniline, two 



CH2- 



-CHo 



H 



H 



H H 



(I) Acenaphthene 



simple derivatives of ben/ene, demonstrated that in the series of ben- 

 zene derivatives, the hypothesis that the substances with high tliermo- 

 dynamic potential and high solubility in lipids were the most active 

 spindle poisons, could not be accepted without some corrections.^^- ^^ 



The Swedish authors,'"- '^^^ '•!■ ''- studying the Allium root tips, 

 came to nearly identical conclusions, linking lipoid solubility with 

 the mechanism of c-mitosis. They studied a large number of com- 

 poiuids, listed in the papers of Ostergren, (cf. also ^''■>) who proposed 

 a theoretical explanation of "narcotized mitosis" which will be dis- 

 cussed in Subsection 17.3-4. It should be pointed out here that all 

 these exjjeriments could easily be carried out on root tips, but that 

 the (onclusions cannot be too rapidly extended to animal cells, which 

 would not resist treatments with strong concentrations of lipoid- 

 soluble substances, often of high toxicity. It is however evident that 

 some drugs known as narcotics in animals, do possess c-mitotic proper- 

 ties. 



i-j.^-^: Narcotics and indifjerent inorganical substances. Among 

 the chemicals capable of inducing narcosis in animals, we have already 

 mentioned chloral hydrate,^-*'- •'•'*• •^•* which is a spindle poison, as 

 shown in Figtne 17.1. Ethylcarbamate (ethylurethane) is a narcotic 

 in animals antl a s]Mndle poison in the egg of Paracentrntiis lividus 

 LK.,'-*-^ in amphibians and in plant cells. -^ In other animal cells, e.g., 

 the intestinal mucosa and the l)one marrow of mannnals, ethylcarba- 

 mate acts like a chromosome poison.^" Chloroform'" and ether are 

 known to arrest cell division in ]jlants and in some eggs of ani- 

 mals.^'^- "' In the corneal cells of Sahniunidra. ethyl alcohol, ether, 

 and chlorethone also prevent the proper activity of the spindle.-'^ 



