甲状腺機能へおよぼす気候の影響 (続報) ウサギ甲状腺I¹³¹摂取率および生物学的半減期の季節的変動

抄録

Some 10 male white rabbits weighing more than 2 kg were monthly studied for a period of 16 months, totaling 176 animal-months. Radioiodine activities were counted externally by holding the animal's neck region over a shielded scintilation detector every 24-hours for five days after the subctaneous injection of 10μc of carrier-free I¹³¹.
Monthly mean values of the rate of I¹³¹ 24-hour uptake by the thyroid gland were changed in a di-phasic form of seasonal variation, rising in severe weathers, both hot and cold, and falling in intermediate mild seasons. Averages of biologic I¹³¹ half-time also varied every month di-phasically throughout a year, being shortened in the winter and even in the summer and, reversely, prolonged in the spring and the fall.
From the findings above-mentioned, the author infers that the iodine-uptake by the thyroid gland and the release of hormonal iodine from the gland are accelerated both in hot and cold weather and are depressed in mild weather such as spring and fall.