抄録
From 10 days of age on, mice were injected 20 times every other day with 0.02 mg of methylthiouracil per gram of body weight, and at 1,5,10,15 and 20 days after withdrawal of administration of methylthiouracil their anterior pituitaries were histologically investigated.
1. Acidophiles showed a slight increase in size a day after withdrawal of administration, but at 5 days after rather decreased in size, while an increase in number and cytoplasmic granulation was seen. Thereafter these changes gradually disappeared, and at 20 days acidophiles showed an almost normal appearance in cytological detail.
2. Beta cells showed an increase in size and a decrease in cytoplasmic granulation at a day after withdrawal of administration, and at 10 days after withdrawal of administration an increase in size of beta cells was seen. However, granulation of beta cells remained decrease at 20 days after withdrawal of administration.
3. Delta cells did not show any appreciable cha n ge.
4. Theta cells were occasionally found regardless of administration.
5. Chromophobes showed a decrease in number at 5,10 and 15days after withdrawal of administration in relation to increase in number of acidophiles. From the sefindings, it is considered that morphological changes of beta cells continue for a relatively long period after withdrawal of methylthiouracil administration.
The authors wis h to express their thanks to Prof. Dr. K. Yamada for his guidance and helpful suggestion. The authors are also indebted to Mr. F. Sanda in the preparation of microphotographs.
