920 K. G. HOSKINS 



Relation between Thyroid and Suprarenal Glands. Several observ- 

 ers have noted an augmentation of the volume of the suprarenal glands 

 following the administration of thyroid material to experimental animals. 

 R. G. Hoskins (a), in 1910, fed young guinea-pigs small quantities (5 to 

 15 mg.) of desiccated thyroid, from birth to the end of 15 days. At the end 

 of this period the animals were killed and the suprarenals weighed. Those 

 of the thyroid-fed subjects averaged 25 per cent heavier than those of 

 the normal controls. 



Iscovesco (1913) prepared an ether soluble material from the thyroid 

 gland and administered it hypodermatically to rabbits. This resulted 

 in a considerable degree of hypertrophy of the suprarenals. 



E. E. Hoskins (1916) made a careful study of the effects of feeding 

 thyroid material to albino rats. He observed that the suprarenals were 

 considerably larger in the experimental than in the control series. In 

 the younger females the augmentation amounted to 14.5 per cent, and in 

 the older females to 16.1 per cent. In case of the males, the augmentation 

 was 36.4 and 38.1 per cent, respectively, in the younger and the older 

 subjects. 



Herring (c) (1917), who employed larger doses of the gland material 

 than did Hoskins, obtained more marked hypertrophy of the suprarenals. 

 The average augmentation of weight in the females was 56 per cent and 

 in the males 41 per cent. Herring noted that the cortex was chiefly 

 affected, though the medulla also seemed to be influenced, as shown by the 

 greater depth and extent of staining of the chromaphil material. 



Hewitt (1920) has confirmed the results of the previous investigators 

 mentioned. The additional observation was made that in the young 

 rat, after the thyroid feeding was discontinued, there was a tendency 

 for the suprarenals to regain their normal weight. 



Kuriyama (1918), on the other hand, failed to observe any signifi- 

 cant hypertrophy of the suprarenals after thyroid feeding, either with 

 large doses for a short time or small doses over a longer period. ~No dif- 

 ference in the epinephrin content of the glands could be detected. Herring 

 (e) (1920) suggests that these experiments, however, were unsatisfactory 

 in that the investigator employed desiccated thyroid of unknown activity 

 in doses which would be toxic if fully active. His animals differed mark- 

 edly in ages and weights and the males and females were grouped together. 

 It is quite possible, too, that the dietary factor played a part, since his 

 animals received only dog biscuit and lard paste, and hence probably 

 suffered from vitamine deficiency, a condition which, as McCarrison and 

 others have recently shown, results in abnormalities of the suprarenals. 



R. G. Hoskins, in 1910, reported some experiments upon guinea-pigs 

 which might be interpreted as indicating suprarenal stimulation by thyroid 

 feeding. To 28 pregnant females commercial desiccated thyroid was 

 fed in small doses. This resulted, in most cases, in abortion or intra- 



