Lintlop S P, Youson J H
Gen Comp Endocrinol. 1983 Feb;49(2):187-94. doi: 10.1016/0016-6480(83)90135-1.
Triiodothyronine (T3) was measured by double antibody radioimmunoassay in the sera of individuals of all stages of the life cycle in the sea lamprey, Petromyzon marinus, and in larval (ammocoetes) and metamorphosing individuals of the brook lamprey, Lampetra lamottenii. There was no significant difference in results from the two species. Although serum T3 concentration did not vary significantly in ammocoetes maintained at the same temperature throughout the year, concentrations in ammocoetes displayed an inverse response to fluctuations in water temperature. Ammocoetes maintained at temperatures of 7 to 10 degrees and 19 to 21 degrees exhibited significantly different circulating T3 levels of 2400 and 1550 ng dl-1, respectively. Therefore, it is expected that there may be some seasonal variation in the levels of the hormone in ammocoetes in their natural environment. A precipitous collapse of the serum levels of T3 was observed by an early stage of metamorphosis (100 ng dl-1) and no significant difference in levels was observed throughout the remaining period of this phase. Young parasitic adults and adult lampreys collected during their spawning migration (upstream migrants) exhibited circulating T3 concentrations of 40 and 30 ng dl-1, respectively. T3 levels in some upstream migrants were below the limit of detection (less than 5 ng dl-1). The metamorphic decline in serum T3 may simply mark the beginning of the lower T3 levels that characterizes the adult serum.
采用双抗体放射免疫分析法测定了海七鳃鳗（Petromyzon marinus）生命周期各阶段个体血清中的三碘甲状腺原氨酸（T3），以及溪七鳃鳗（Lampetra lamottenii）幼体（沙隐虫）和变态期个体血清中的T3。两种七鳃鳗的检测结果无显著差异。虽然全年饲养在相同温度下的沙隐虫血清T3浓度无显著变化，但沙隐虫血清T3浓度对水温波动呈反向反应。饲养在7至10摄氏度和19至21摄氏度的沙隐虫，其循环T3水平显著不同，分别为2400和1550 ng dl-1。因此，可以预期，在自然环境中，沙隐虫体内该激素水平可能存在一些季节性变化。在变态早期观察到血清T3水平急剧下降（降至100 ng dl-1），并且在变态期的剩余阶段未观察到水平有显著差异。在产卵洄游期间捕获的幼年寄生成体和成年七鳃鳗（溯河洄游个体），其循环T3浓度分别为40和30 ng dl-1。一些溯河洄游个体的T3水平低于检测限（低于5 ng dl-1）。血清T3在变态期的下降可能仅仅标志着成体血清中较低T3水平的开始。
