THE THYROTROPIC HORMONE 



pig's thyroid is highest during the ovarian luteal stage and 

 lowest during the follicular stage. Female thyroids appeared 

 to be more active than those of male animals. Likewise, 

 Franck (1937) declared that the injection of oestrone (250- 

 2,500 international units) into guinea pigs is followed by his- 

 tological signs of thyroid inactivity. The young male albino 

 rat was the experimental animal chosen by Amilibia, Men- 

 dizabal, and Botella-Llusia (1936). They believed that the 

 daily injection of 200 mouse-units of oestrin ("Progynon") 

 for 5 days causes the histologic changes commonly described 

 as characteristic of increased thyroid activity and that this 

 is due to an effect on the anterior pituitary. Also, they stated 

 that a stage of thyroid inactivity followed that of activity.''' 

 According to Cramer and Horning (1938), the injection of 

 extracts containing thyrotropic hormone prevents the follow- 

 ing effects of the prolonged administration of oestrin to 

 mice: (i) the spontaneous development of mammary carci- 

 noma in a special strain of mice with a high, spontaneous in- 

 cidence, (2) the development of the mammary gland in male 

 mice, and (3) alterations of the anterior pituitary, likewise 

 caused by oestrin, such as marked congestion and disappear- 

 ance of the oxyphils. 



Gehme (1936) concluded that one adrenal cortical extract 

 ("Cortidyn"), but not a second called "Pancortex," prevents 

 the elevation of basal metabolism due to thyrotropic hor- 

 mone. However, the histological signs of thyroid stimulation 

 appeared as usual. The effect observed appeared not to be 

 due either to ascorbic acid or to tyrosine. 



An increased rate at which isolated strips of the auricle 

 beat can be observed, if guinea pigs receive injections either 

 of thyroxine or of thyrotropic hormone (Ferrannini, 1936). 

 From observations of the heart rate in rabbits, Rihl, Oest- 

 reicher, and Reiss (1936) concluded that the effects of thy- 

 roxine are strikingly different from those of thyroid hormone 



''• The similar injection of progesterone as i Clauberg-unit daily was found to 

 have no effect. 



[187I 



