The Primary Toxic Reaction and Mitosis

According to most authors, and our studies, a 0.1% primary non-toxic solution of DNCB in acetone causes no macroscopically visible reaction and no histological alterations on the flank and the nipple of guinea pigs. 

Mitotic activity can also be observed with certain eczematogenic derivatives of benzene (Bujard, W. Jadassohn, Brun and Paillard, 1953) (Table 2). 

These experiments show that a substance dissolved in a certain solvent (at a certain concentration) cannot be said to be ineffective, because only a histological examination could reveal certain lesions such as the increase of mitosis. 

The primary toxic reaction of DNCB has been histologically examined by various authors. Among others  

Nilzen (1952) admits that the primary irritation caused by DNCB in unsensitized guinea pigs does not differ from the specific reaction of sensitization in any case, there is no clear difference. 

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