230 



Colchicine 



TABLE 9.7 

 Mitotic Index in Organs of Pregnant Guinea Pig 



I: without colchicine 



II: 9 hours after 0.625 mg./lOO g. colchicine 



A: embryos less than 5 mm. long 



B: embryos from 5 to 15 mm. 



C: embryos longer than 15 mm. 



(After Cavallero^^) 



Hypophysis 



(anterior lobej . . 



Thyroid 



Parathyroids 



Adrenal cortex .... 



Adrenal medulla . . 



Langerhans' islets. . 



Corpus luteum .... 



Kidney 



Pancreas (exocrine) 



Liver 



Controls 



I 







0.2 



































II 



2 



0.3 



1 











1 



2 



0.5 







A 



I 



5 

 2 

 1 

 2 







0.3 



1 



2 



1 







II 



17 



7 



14 



4 

 



B 



I 



1 

 1 



















6 



9.5 











II 



4 

 

 

 6 

 5 

 10 

 





 

 

 

 

 



* 



0.5 











II 



6 

 3 



2 

 1 





 

 5 



18 

 5 

 



* The figure given in the original paper has been omitted because of a typographi- 

 cal error which it has not been possible to correct (Cavallcro, personal communication). 



more remarkable that the growth hormone, somatotropin (STH) , 

 has only been studied ^vith the colchicine method in a single paper, 

 which pointed to stinudation ot hemopoiesis."* This shows that many 

 pathways remain open. The results obtained with other hormones 

 are good evidence that important and inisuspected findings still re- 

 main before us. 



().4-2: Sex hormones. These are poAverful stimidants of mitotic 

 growth. Some of the results with estrogens have been reported in the 

 first paragraph of this chapter.-- ^^ It was not always realized that 

 estrogens may stimidate growth in other epithelia than those of the 

 genital tract. In his observations on mice, Bidlough, using colchicine 

 to detect the increased mitotic activity, demonstrated stimulation in 

 most tissues, including connective tissue.-* In further experiments, 

 this author has called attention to a remarkable effect of estrogens. 

 Figure 9.6 shows that colchicine increases the mitotic index of the 



