254 



ADVENTURES IX RADIOISOTOPE RESEARCH 



Lecithin 



Fatty acid 



+ 

 Lysochitin 



Fatty acids 



Glycerophosphorie ester 

 of Cholin 



Cholinphosphatase 



Cholin -f Glycerophos- 

 phorie acid 



Glycerophosphatase 

 Glycerin + Phosphoric acid 



The figures in our experiments show clearly that the ratio of labelled 

 lecithin phosphorus to labelled phosphorus other than that from lecithin 

 in the brain increases with time. The amount of labelled lecithin produced 

 within 1 hour in the brain of a rat can be estimated as lying between 

 0.08 and 0.0008 mgm. 



In starting this research we contemplated the possibility of the for- 

 mation of labelled brain lecithin being influenced by nervous action. 

 No effect of nervous actions on chemical processes in the brain has 

 yet been ascertained; the dependence of the latter on the former must 

 be described by a curve where a very large increase in the abscissa 

 (nervous action) corresponds to a minimal change in the ordinate 

 (chemical effect). To test this possible effect of nervous action it 

 would be necessary to carry out a very large number of experiments. 



Summary 



By using laVjclled (radioactive) phosphorus as indicator, it was found that one 

 hour after the subcutaneous injection of labelled sodium phosphate, labelled 

 lecithin was already formed in the brain tissue of fully grown rats. Similar experi- 

 ments were also carried out with fully grown mice and rabbits. The losult proves 

 that a constant breakdown and building up of lecithin takes place in the brain 

 tissue presumably under enzymatic action. 



References 



O. Chievitz and G. Hevesy (1935) Nature 136, 754. 



O. Chievitz and G. Hevesy (1934) Kgl. Danske Vidensk. Sehk. Biol. Medd. 



XIII, 9. 

 S. Belfakti, a. Contardi and A. Ercoli (1936) Ergehn. Enzymforsch. 5, 213. 

 C. Artom, L. Perkier, M. Santagello, G. Sarzana and E. Segre (1934) Nature 



139, 83G. 



