Functions of the Suprarenal Cortex 53 



hours in an incubator a considerable amount of a substance giving the 

 reactions of adrenalin accumulates within it. But according to the in- 

 vestigations of Bayer the results obtained are not ascribable to adrenalin, 

 but to products of protein decomposition. The facts that the cortex be- 

 comes enlarged during pregnancy and is small in cases of deficient sexual 

 development, and that changes have been described (in the guinea-pig by 

 Kolmer) in the cortical cells accompanying the phases of the oestrous cycle, 

 seem to afford evidence of some relationship between the functions of the 

 cortex and the generative glands ; but whether this is direct, or operates 

 through other ductless glands — such as the thyroid and pituitary — is not 

 known. The occurrence of a connexion between the development of the 

 sexual organs and that of the suprarenal cortex has been especially insisted 

 upon by Glynn, who is of opinion that the cortex is concerned with the 

 differentiation and growth of the sexual cells. 



It has also been suggested that a function of the cortex may be to 

 neutralise deleterious products which are formed in the processes of 

 metabolism or which are introduced from outside. But this supposition 

 has received no support as the result of experiments. 



One of the most striking facts connected with the cells of the cortex is 

 their richness in lipoids and fats. These have been chemically investigated 

 by many workers. In an analysis by Biedl the suprarenals of the pig 

 yielded 7461 per cent, of water and 2539 per cent, of dry residue. Of the 

 latter, 61 12 per cent, consisted of proteins, etc., and 38 88 per cent, of 

 lipoids — besides some insufficiently distinguishable extractives. In this 

 analysis the medulla was included : as this is poor in lipoids the lipoid con- 

 tents of the cortex must have a much higher value — far higher than any 

 other non-nervous tissue. 



Besides globules of what appear to be fat, a doubly refracting substance 

 is found in the cortical cells of most animals — varying in amount and in its 

 position in the cortex in different species. In some it takes the form of 

 doubly refracting crystals. Elliott and Tuckett regard both the fatty 

 and the doubly refracting substance as products of secretion of the cells. 

 They find that the doubly refracting substance increases in amount during 

 rest and diminishes as the result of muscular activity. In the guinea-pig 

 there are numerous brown-coloured granules in the cells — chiefly in the 

 zona reticularis — and Elliott and Tuckett state that these also accumulate 

 during rest and quickly disappear with muscular work, fatty globules 

 taking their place. The doubly refracting lipoid substances seem to con- 

 sist mainly of lecithin and cholesterol — the latter in the form of esters. 

 Rosenheim and Tebb extracted from the suprarenal cortex of the ox various 

 fatty acids, cholesterol esters, and phosphatides, such as sphingomyelin ; 

 but not free cholesterol. 



The suggestion that the suprarenal cortex may be a seat of manufacture 

 of the lipoids of the body and may especially be related to the formation 

 and development of the myelin of the medullated nerve-fibres is attractive. 



