THE EFFECT OF TF1YR()II)-FEKI)IX( ; OX THK WKICHT OF 

 THE SUPKAKEXALS AXJ) oX THKIH ADKEXAIJX COX- 

 TEXT. By P. T. HEiatiN.;. (From iIk- Pliysiol()<;y J Apartment, 

 University of St Andrews.) 



{Received Jor publication. \d>ih Auijasl 191G.) 



In a previous paper tlie author (11) showed that the adniinistration of 

 raw thyroid in lar(;e doses to cats increases the amount of adrenalin in 

 the suprarenals of these animals. There was also evidence that it 

 increases the weight of the suprarenals. The importance of these 

 conclusions led tlie author to investigate the ett'ect of smaller doses of 

 thyroid in a more extensive series of experiments. The results upon the 

 suprarenals are recorded in this paper. 



That administration of thyroid causes h3'pertroph3' of the suprarenals 

 in new-born animals was shown by Hoskins (13) in 1910. Hoskins 

 fed guinea-pigs from the day of birth for 15 days with small amounts, 

 5 to 15 mg., of desiccated thyroid, and then weighed the suprarenals, using 

 as controls guinea-pigs of the same age. He obtained an average 

 hypertrophy of 25 per cent, in the suprarenals of the thyroid-fed animals. 

 Further experiments showed that adult guinea-pigs fed with thyroid 

 throughout pregnancy give birth to young in which the average weight 

 of the suprarenals is below the normal. This deficiency in weight was 

 interpreted by Hoskins as indicating a reaction in the suprarenals of the 

 offspring to increase of adrenalin in the blood of the mother brought 

 about by thyroidism. Hoskins recorded other experiments which wei'e 

 inconclusive, but believed that his evidence on the whole supported the 

 theory that the thyroids normally stimulate the suprarenals to hyperplasia, 

 though he made the reservation that the hypertrophy might be due to 

 toxin in the thyroid employed. 



A close relationship between the functions of the thyroid and 

 the medulla of the suprarenals is suggested by the work of Asher and 

 Flack (1). Several observers, Fraenkel (9), Broking and Trendelen- 

 burg (2), and Krause (14), employing different methods, have recorded 

 an increase of adrenalin in the blood of patients suffering from 

 exophthalmic goitre, a disease which most authorities believe to be 

 characterised by excessive thyroid secretion. Ott and Scott (15) further 

 ascertained that intravenous injection of thyroid extract increases the 

 adrenalin in the blood of experimental animals ; but they also obtained a 

 similar increase by injecting extracts of other organs. Sir Edward 



