Age Factor in Some Prenatal Endocrine Events 27 



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DISCUSSION 



Amoroso: It is evident from Professor Jost's account that the effects 

 of decapitation of the foetus are many and varied, and that by utilizing 

 this technique — so familiar in his country — he has contributed much to 

 our understanding of the endocrine climate of the foetus. He has raised 

 a number of interesting points, not the least important of which is the 

 self-perpetuating nature of the urogenital system in the absence of the 

 testes after a certain stage in development has been reached. He has also 

 called attention to the sundry histochemical reactions that he employs 

 as evidence in support of his thesis. It seems reasonable therefore that 

 Professor Wislocki should open the discussion. 



Wislocki: There is a point I should like to raise with regard to Prof. 

 Jost's report. It concerns the changes he noted in glycogen storage and 

 synthesis in the liver, following decapitation. Claude Bernard, in 1859, 

 first proposed that the placenta is a deputy for the foetal liver until 

 such time as the latter becomes physiologically capable of forming 

 and storing glycogen. How the placenta gives up this function I shall 

 demonstrate tomorrow in several lantern slides which will show the 

 disappearance of glycogen from the rat's placenta in relationship to its 

 appearance in the foetal liver. 



It would be interesting to know, with respect to the dramatic change 

 which you have demonstrated in the liver following decapitation, 

 whether placental glycogen persists, while its appearance in the liver 

 is postponed? Is the placenta also a target organ of the pituitary? If it 

 is not, does it then maintain its function of glycogen storage following 

 decapitation? 



Jost: We examined this question with Jacquot, but only a few cases 

 were studied. One difficulty with this study is the high variability of 

 the glycogen content of the maternal placenta from one individual to 

 another at the stage we studied (28th day). But as far as we could see, 

 we observed no clear change from the normal in the placenta of decapi- 

 tates. This means that the placenta of the decapitates did not contain 

 more glycogen than that of controls, despite the low glycogen content 

 of the liver. Likewise the effect on the placenta of high doses of 

 hydrocortisone given to the foetus was not too evident, since the 

 placenta of the treated foetuses did not very clearly exceed the high 

 range of individual variability. Have you any information on that 

 matter, Prof. Huggett? 



Huggett: With regard to controlling glycogen in rats and rabbits 

 chemically, Prof. Jost is quite correct in saying that there is some factor 

 causing considerable variation. But if you take a number of animals and 



