246 



Colchicine 



idea of a fixation of the alkaloid. One of the purposes of this book 

 is being fulfilled whenever similar contradictions between work done 

 in widely separated fields of research are brought to light. 



9.6: Wound Healing 



The histological changes found in wounds after injections of col- 

 chicine were some of the most surprising observed by A. P. Dustin, 

 Sr.^- They appeared to give good support to the theory that a true 

 mitotic excitation followed the injection of the alkaloid. Experiments 

 were performed in rats. Two parallel incisions were made in the 

 dorsal skin, and alcurone grains inserted as an irritant in the wounds 

 before suturing. One of the scars was removed as a control at the 

 time colchicine was injected. The dose was 1.25 mg/kg and the ani- 

 mals were killed 9 hours later. This method made available some new 

 facts about w^ound healing and the formation of granulation tissue 

 near the alcurone grains. The endothelial cells are the first to divide. 

 Extraordinary pictures of capillaries with up to 10 c-mitoses in a 

 single section were observed. These cells appeared swollen. The 

 rapid mitotic growth was not noticeable without the use of the colchi- 

 cine tool.^- 



In nerve regeneration, the alkaloid, by increasing the numbers 

 of mitoses, makes clear that their repartition is different on both 

 sides of a section. This may result from the influence of the disintegra- 

 tion products of myelin on the division of the Schwann cells (Fig. 

 9.15) .36 



16 17 



Fig. 9.15 — Colchicine-mitoses in a regenerating nerve of the rat. The shaded zone is 

 that of cicatrisation following sectioning. There are more mitoses in the Schwann cells 

 in the peripheric end, at left, than in the central part of the nerve. (After Delcourt ) 



