The binding capacity of specific receptors for dexamethasone (11β,17α,21-trihydroxy-9α-fluoro-16α-methyl-1,4-pregnadiene-3,20-dione) in the cytoplasm of the thymus of rats bearing AH 130 (solid-type) tumors decreased significantly during tumor growth. Adrenalectomy restored the binding capacity of the glucocorticoid receptors and the weight of the thymus to nearly the normal values in rats bearing tumors. The affinity of these receptors for dexamethasone was very low in rats bearing tumors, but it was also restored to nearly the normal value by adrenalectomy.
Presented at the John E. Fogarty International Center Conference on Hormones and Cancer, March 29 to 31, 1978, Bethesda, Md. Supported by grants-in-aid for Cancer Research from the Ministry of Education, Science and Culture, Japan, and the Osaka Anticancer Association, Japan.