352 GENERAL DISCUSSION 



This can be, in the first place, the nuclear membrane itself — then the 

 data submitted by Bai'endsen are comprehensible, namely that injury 

 to it in any place by one particle leads to loss of electrolytes and nucleo- 

 teins and to the destruction of the biosynthesis of DNA, in consequence 

 of which the damage to the chromosomes acquires a manifest character. 

 Then the data of Barendsen, of Errera and of Hollaender are imme- 

 diately exi^licable. There can be, in the second place, damage to the 

 cytoplasmic membranes which facilitates the interaction of enzyme 

 and substrate — and we shall then obtain the activation of a series of 

 enzymes as is indicated in Bacq and Alexander's first pajier, and in 

 our paper. This may also explain the interesting data of Hug and the 

 data of Kuzin which are in complete agreement with that obtained in 

 our laboratory for the interaction of polyphenoloxidase with tannin 

 in tea-leaves and of lipoperoxidase with unsatui'ated fatty acids. The 

 primary function in this case is not the production of peroxides or 

 semi-quinones but the destruction of some intracellular structures 

 which facilitates the contact of enzyme and substrate. However, we 

 have not studied alterations in mitosis, but I would like once more to 

 emphasize the great significance and interest of Kuzin's data. 



The damage to the enzymes is not evidently by itself a primary 

 factor in radiobiological action. It may be assumed that the damage 

 to the mitochondria is also not a primary phenomenon. There are thou- 

 sands of them in the cell, and thei'e is no foundation for the supposition 

 that any one of these structures is unique. It follows that damaging 

 them does not satisfy the primary criteria. 



It is evident that in the cell there are only two kinds of uniqueness 

 — the uniqueness of the chromosomes and the uniqueness of the flow 

 of biochemical transformation, Avliich is regulated by the nuclear, and 

 by certain cytoplasmic, membranes. All the basic problems of radio- 

 biology as shown in particular in the article which we published f can 

 be explained by damage to these. The concept of damage to the mem- 

 branes is connected in radiobiology with the general theory of open 

 systems (but it does not form the basis of the self-adjustment and 

 homeostasis of living organisms, about which Frank made some com- 

 ment). There is no need to juxtapose chromosome damage and mem- 

 brane damage. Both the studies on the structure of biopolymers and 

 also the theory of open systems are internally connected and form the 

 two physico-chemical bases of radiobiology. 



tumerman: Unfortunately, our discussion has diverged from considera- 

 tion of the problem of the single nature or the plurality of primary 



t Biophysics (Russ.), 1957. 



