Abstract
In former investigations Loeb 1 , 3 and Loeb and Kaplan 2 have shown that feeding of tablets of anterior pituitary substance (Armour & Co.) prevents, in the guinea pig, compensatory hypertrophy which otherwise occurs in many cases after the greater part of the thyroid has been extirpated. H. A. McCordock 4 through feeding of these tablets prevented the marked cell proliferation which occurs in the guinea pig after administration of potassium iodide. There are also prevented the slight changes in colloid and in the size of the acinus cells caused by iodine. These experiments proved that in Armour's Anterior Pituitary preparation there is present a substance which prevents growth processes (hypertrophy and hyperplasia) in the thyroid of the guinea pig.
However, in larvae of amphibia, it has been shown that removal of the anterior pituitary may cause atrophic changes in the thyroid gland (B. M. Allen, 5 P. E. Smith 6 ) or, conversely, that injection of acid extracts of anterior pituitary may stimulate the thyroid gland and cause morphological changes indicative of active secretion (E. Uhlenhuth and S. Schwartzbach 7 ). These facts suggested to us the possibility that there may be present, also, in the mammalian anterior pituitary, substances which have a stimulating effect on the thyroid gland.
We prepared, from dried and powdered anterior pituitary of cattle, acid as well as alkaline extracts (subsequently neutralized) of which we injected daily 1 cc. intraperitoneal in each of a series of 19 guinea pigs, an additional animal as well as animals used in other series serving as controls. We used 2 different concentrations in both the alkaline and the acid extract. The injections extended over periods varying between 7 and 19 days.
Get full access to this article
View all access options for this article.