Lintlop S P, Youson J H
Gen Comp Endocrinol. 1983 Mar;49(3):428-36. doi: 10.1016/0016-6480(83)90206-x.
The in vitro binding capacity of triiodothyronine (T3) to hepatocyte nuclei was determined for lampreys (Petromyzon marinus L.) at different phases of the life cycle. The binding of T3 to nuclei in ammocoetes (larvae) is of high affinity (Kd = 2.9 X 10(-10) M) with a maximum binding capacity of 1.89 pg T3 X micrograms DNA-1. Binding capacities of metamorphosing individuals, young parasitic adults, and upstream-migrant adults were 2.40, 0.78, and 0.12 pg T3 X micrograms DNA-1, respectively. With the exception of the value obtained from the upstream migrants, the hepatocytes of lampreys have a higher binding capacity for T3 than most other vertebrates. The decline in serum T3 at the beginning of metamorphosis cannot be accounted for by increased binding of this hormone in the liver. It is still unclear whether T3 plays any role in lamprey metamorphosis.
测定了生命周期不同阶段的七鳃鳗（海七鳃鳗）中三碘甲状腺原氨酸（T3）与肝细胞核的体外结合能力。T3与沙隐虫（幼体）细胞核的结合具有高亲和力（解离常数Kd = 2.9×10⁻¹⁰ M），最大结合能力为1.89 pg T3×μg DNA⁻¹。变态期个体、年轻寄生成体和溯河洄游成体的结合能力分别为2.40、0.78和0.12 pg T3×μg DNA⁻¹。除了溯河洄游个体的数据外，七鳃鳗的肝细胞对T3的结合能力高于大多数其他脊椎动物。变态开始时血清T3的下降不能用肝脏中这种激素结合增加来解释。T3在七鳃鳗变态过程中是否起任何作用仍不清楚。
