RETURNAn Effect of Thyroid Hormone on Histamine Release from the Peripheral Leukocytes in Unsensitized and Sensitized Guinea Pigs
Yuji Kawasaki, Yutaka Hitsuda and Takao Sasaki
Third Department of Internal Medicine, Faculty of Medicine, Tottori University, Yonago 683, Japan
We studied the effects of the thyroid hormone on histamine release (HR) from peripheral leucocytes in unsensitized and sensitized guinea pigs. The animals were sensitized with ovalbumin (OA) on days 1 and 3. Four animal groups were treated with L-thyroxine (T4) [sensitized plus T4-treated (group ST, n=16) and T4-treated (group T, n=9)] or vehicle [sensitized (group S, n=9) and control group (group C, n=9)] on days 30, 31 and 32. Spontaneous HR (SHR) from the peripheral leucocytes of groups C, T and S did not differ. SHR in group ST was significantly higher than that in group C. There were no statistical differences in concanavalin A (Con A)-induced HR in groups C and T. HR in group S only differed from that in group C by 100 µg/mL. However, the 1 and 10 µg/dL Con A-induced HR in group ST was greater than that in group C. OA-induced HR from sensitized leucocytes was also enhanced by T4. Therefore, it was concluded that thyroid hormones enhanced SHR, as well as Con A- and OA-induced HR from peripheral leucocytes in sensitized guinea pigs. These findings suggest that an increase in the thyroid hormone may adversely affect the bronchial state via a release of histamine.
Key words: immunohistochemistry; frozen section; intraoperative diagnosis