THE PITUITARY BODY 



tropic hormone; he performed assays in the rabbit by in- 

 jecting the extract of urine intravenously. 



Goiter was produced by Remington (1937) in rats by feed- 

 ing a diet containing too little iodine. The effects of thyro- 

 tropic hormone were no less difficult to elicit in such rats than 

 in normal rats. On the other hand, thyroids of rats, goitrous 

 for unknown reasons, were found by Anderson and Collip to 

 be abnormally sensitive to the thyrotropic action of anterior 

 pituitary extract. 



The effects of iodides will be considered in this section. 

 Friedgood (1936) reported that the administration of sodium 

 iodide caused a remission of the symptoms of hyperthyroidism 

 in guinea pigs receiving anterior pituitary extract. He con- 

 cluded that the remission resembled that produced in human 

 beings with exophthalmic goiter or with the hyperthyroidism 

 of early acromegaly. Weil and Bernheim (1936) made auto- 

 transplants of the thyroid after total thyroidectomy in the 

 guinea pig. The effect of 70-400 units of thyrotropic hor- 

 mone, indicated by histological signs of stimulation of the 

 thyroid, could be antagonized by the administration of KI; 

 however, a much greater antagonistic action was produced 

 by thyroxine and, to a less extent, by diiodotyrosine. The re- 

 sults of Anderson and Evans (1937) were different from those 

 of the authors just cited. Anderson and Evans concluded that 

 the coincident administration of KI does not interfere with 

 the production of thyroid hyperplasia by thyrotropic hor- 

 mone but that the iodide prevents the liberation of thyroid 

 hormone into the blood, so that a calorigenic effect does not 

 appear. This conclusion was based on experiments in normal 

 guinea pigs and hypophysectomized rats.'^ 



Extracts containing thyrotropic hormone in relation to anti- 

 hormone effects. — Some authors believe that a small amount 

 of antithyrotropic substance is present in normal serum 



■' See also Franck's interpretation (1937) of histological changes in the pituitary 

 after the injection of anterior pituitary extract with or without Lugol's solution or 

 diiodotryosine. 



[192] 



