STUDIES ON THE BEHAVIOUR OF CHOLESTEROL WITHIN THE ANIMAL BODY

IV. The rôle of thyroid gland in the content of cholesterol in each organ and tissue

Abstract

The main results obtained in the foregoing II, III and IV communications, may be summarized as follows.
1. Under normal conditions the contents of free cholesterol within the animal body is strikingly constant.
2. The amount of free cholesterol in many of the active tissues is increased by the injection of adrenalin. This erect of adrenalin is entirely suppressed by the previous treatment with ergotoxin. The excitant period of ergotoxin however evokes the sane effect as adrenalin. The excitation of the sympathetic nerve ending therefore seems to cause inereas in the free cholesterol content of tissue.
3. The effect. of adrenalin in increasing the free cholesterol content of tissue is found without any regard to the presence or absence of thyroid gland.
4. The extirpation of thyroid gland induces the reduction in the amount of oxygen consumption. Together with this change the reduction of free cholesterol content in brain, lung and skeletal muscle i s observed.
5. The amount of ester-cholesterol in adrenal bodies and blood plasma is increased in thyroiddepleted animal. This effect is not influenced by the injection of adrenalin at all. The hormon of thyroid gland seems to play some role in the free cholesterol formation from its ester.
I wish to express my sincere thanks to Prof. S. Kakiuchi for his kind advice throughout the course of the investigation.