Comparison of Effects of Various Preparations of Anterior Pituitary Gland on Thyroid of Guinea Pig

Abstract

In a former communication, we reported that the thyroid gland of guinea pigs which received injections of acid or alkaline extract of the anterior pituitary gland within a short time showed such a remarkable hypertrophy that it closely resembled the thyroid seen in pronounced cases of Graves disease. These findings were in marked contrast to the fact that the feeding of Armour's tablets of anterior pituitary prevented or greatly inhibited compensatory hypertrophy in thyroidectomized guinea pigs. Preparation of Extracts. The anterior pituitary of cattle was freed completely from other parts of the hypophysis, then dried and powdered. Five grams of the dried powder were extracted with 100 cc. of 0.5% acetic acid or with 100 cc. of 0.1% sodium hydroxide for a period of 24 hours, in ice chest. The fluid was separated from the residue by filtration, neutralized to pH 7.8 (Phenol Red), refiltered to remove a protein precipitate which falls out at the isoelectric point. The filtrate was then passed through a Seitz bacterial filter to render it sterile. Experimental. Silberberg, in the course of experiments carried out in this laboratory observed that there was a distinct hypertrophy in the thyroid gland of the guinea pig as early as one day after the injection of 1 cc. of acid extract of the anterior pituitary. Following this, we made a comparative study of the action of acid and alkaline extracts on the thyroid gland and also on the sex organs. One group of animals was injected daily with 1 cc. acid extract, and another with 1 cc. of alkaline extract. On each day, beginning with the second day of the experiment and ending with the seventh, we removed the thyroid gland from one guinea pig of each set.