갑상선 기능변조가 성호르몬 결합단백에 미치는 영향

Abstract

Carrying out thyroidectomy and administering trHodothyronine CT.) suhsequently in adult male rabbits. the effect on sex hormone binding globulin and plasma testosterone activity were investigated. Experimental animals were divided into two groups according to the control plasma concentrations of testosterone. On the 1st day thyroid glands were removed, then on the 3rd and 5th days, T. (0.5mg/kg, body wI. ) were administered intraperitoneally. Venous blood samples were taken on the morning of the 1st, 3rd, 5th and 7th days. Plasma total testosterone concentration and SHBG binding capacity were determined by radioimmunoassay and Rosners ammonium sulfate precipitation method. Followings are the results obtained: L Control levels of plasma testosterone , SHBG binding capacity and their ratio were 335. 2±137. 3ng/ 100ml, 9.10 士O. 82~g/100ml ， 106.7±43. 8, respeclively. 2. After removal of thyroid glands, plasma testosteron" decreased, SHBG binding capacity increased, therefore their ratio increased. In low testosterone group !>lasma testosterone increased but not exceeded the level in high testosterone group_ 3. By T3 administration plasma testosterone increased and SHBG binding capacity showed decreasing tendency in both of the groups_ 4. Further administration of T3 showed decreasing tendency in testosterone concentration but increasing tendency in SHBG binding capacity. From the above results we concluded that the acute changes in SHBG binding capacity during thyroid disorder were not ascribed to the direct eκects of T, but rather to the indirect effect through the changes in steroid such as testosterone.