HUGO THEORELL 



certain nerve receptors, transforming a change in ion concen- 

 tration to a potential change and an electrical discharge. 



Some recent work by Zotterman et al. (37) on the response 

 in taste fibers from the cat tongue to stimulus by various salt 

 solutions applied on the tongue give some support to this theory. 

 They have found particular "water" fibers that respond to pure 

 water, and to solutions of acetate and formate, when they are 

 rinsed over the tongue. Salts of strong acids (NaBr, Nal, 

 NaNOs, NaCl, KCl, and CaClg) all abolished the response. It 

 should be recalled that acetate and formate have no effect on the 

 dissociation of O.Y.E., whereas the anions of strong acids all 

 dissociate it. 



Finally, the strong effect of substances like cyanide, hydrox- 

 ylamine, pyruvoxim, and formate on the reaction velocity in 

 the ADH-system is perhaps of considerable interest from a 

 wider point of view. There is no reason to believe that any of 

 these substances, with the possible exception of formate, are 

 present in detectable concentrations in the living cells. But 

 since these chemically very different substances can all react 

 with the pyridine ring we shall have to look for such effects with 

 substances known to occur physiologically in the cells. This may 

 lead to the discovery of mechanisms for the coordination and reg- 

 ulation of the different enzymatic activites in the cells. 



References 



1. Boeri, E., A. Ehrenberg, K. G. Paul, and H. Theorell, Biochim. et Biophys. 

 Acta, 12, 273 (1953. 



2. Bonnichsen, R., and A. Wass^n, Arch. Biochem., 78, 361 (1948). 



3. Burton, R. M., and N. O. Kaplan, J. Biol. Chem., 211, 447 (1954). 



4. Chance, B., and J. B. Neilands, J. Biol. Chem., 199, 383 (1952). 



5. Kaplan, N. O., and M. M. Ciotti, J. Biol. Chem., 211, 431 (1954); 

 N. O. Kaplan, M. M. Ciotti, and F. E. Stolzenbach, ibid., 211, 419 (1954). 



6. Kuhn, R., and P. Boulanger, Ber., 69, 1557 (1935). 



7. Kuhn, R., and G. Moruzzi, Ber., 67, 888 (1934). 



8. Kuhn, R., and H.Rudy, 5fr., 59,2557(1936). 



9. Meyerhof, O., P. Ohlmeyer, and W. Mohle, Biochem. Z., 297, 90 (1938). 



306 



