Effects of yin-tonics and yang-tonics on serum thyroid hormone levels and thyroid hormone receptors of hepatic cell nucleus in hyperthyroxinemic and hypothyroxinemic rats

Hyperthyroxinemia model was made by giving thyroid tablet suspension to Wistar rats and hypothyroxinemia model was made by thyroidectomy. We measured serum thyroid hormone levels by RIA and the parameters of triiodothyronine receptors in rat hepatic cell nucleus by radio-ligand binding assay: Maximal binding capacity (Bmax) and Dissociation constant (Kd). It is found that (1) Yin-tonics can lower serum thyroid hormone levels and Bmax of hepatic nuclear T3R of hyperthyroxinemia rat from 167.14 +/- 25.62 fmol/100 micrograms DNA to 98.98 +/- 15.24 fmol/100 micrograms DNA, P less than 0.001. (2) Both Yang-tonics I and II can raise serum thyroid hormone levels of hypothyroxinemia rats, but not Bmax of hepatic nuclear T3R. Yang-tonics I even lowers Bmax. All the Chinese herbs have no effect on the Kd of rat hepatic nuclear T3R. The results may have some value in studying the effects of Chinese medical drugs.