Chemical Messengers 83 



At least six of these compounds have been isolated from the sup- 

 rarenal cortex. Some of them seem to be concerned with the break- 

 down of carbohydrates and proteins. When given in excess they have 

 an anti-insulin effect and cause a rise of blood sugar which amounts 

 to temporary diabetes. Others are concerned in maintaining the 

 balance of inorganic salts in the body — the preponderance of sodium 

 and chloride in the fluids of the body and of potassium and phosphate 

 in the cells. 



It was found by Dr Philip S. Hench, of the Mayo Clinic, that one 

 of the first group of substances, namely, cortisone or compound E 

 originally isolated by E. S. Kendall, has a palliative effect on some 

 types of rheumatoid arthritis. Unfortunately the supply of cortisone 

 from suprarenal glands is very small and the expense of treating only 

 a few patients with gland extracts was enormous. The substance can 

 be obtained synthetically from a bile-acid but the development of a 

 method of manufacture has been shortened by the discovery that 

 many plants contain steroids which can be converted into cortisone 

 in fewer steps. 



One important function of cortisone and other steroids made by 

 the adrenal cortex is to protect the tissues against the effects of stress. 

 The mechanism of this is unknown, but the increased cellular action 

 required after shock and injuries depends upon the presence of these 

 substances. 



We come now to the hormones secreted by the male and female 

 sexual organs. They govern the sexual cycles and all the processes 

 of reproduction. They also determine the secondary sexual characters. 

 A hundred years ago Berthoud showed that the sex glands of a cock 

 transplanted into a hen caused her to develop a cock's comb. The 

 capon develops only a rudimentary comb, but the male sex hormone 

 from any species, even in minute amounts, causes its full develop- 

 ment. Males have been known to turn into females, and vice versa, 

 when their sex glands are atrophied and injured. Maleness and 

 femaleness is the result of a hormonal balance which is easily 

 disturbed. 



Similarly extracts from the ovaries have a powerful effect in causing 

 females to 'come on heat'. A number of substances (oestrogens) have 

 been isolated which produce this effect to a greater or lesser degree. 

 The sex hormones are, in general, very similar to each other — in 

 fact the differences between the characteristic male and female hor- 

 mones are minor ones. 



Finding out how these compounds are related to each other is like 

 solving a complicated jig-saw puzzle in which many of the pieces are 

 missing. Quite a number of synthetic compounds which are not 



