Wright G M, Youson J H
J Exp Zool. 1977 Oct;202(1):27-32. doi: 10.1002/jez.1402020104.
Thyroxine (T4) concentrations in samples of fresh sera taken from fed and unfed larval (ammocoetes) and metamorphosing anadromous sea lamprey (Petromyzon marinus) were measured by means of radioimmunoassay. T4 levels in unfed ammocoetes after a 1-month period were not significantly different from those of the fed ammocoetes. Nutritional state of ammocoetes therefore does not seem to affect their serum T4 levels. Serum T4 concentrations decreased abruptly at the onset of metamorphosis and declined to levels observed in spawing adults (Leloup and Hardy, '76; Packard et al., '76) by the middle (stage 3) of metamorphosis. No significant change in serum T4 levels occurred between stage 3 to the end of metamorphosis. The possible significance of decline in serum T4 levels to the metamorphic event in lamprey is discussed.
通过放射免疫分析法测定了取自摄食和未摄食的幼体（沙隐虫）以及变态溯河洄游海七鳃鳗（海七鳃鳗）新鲜血清样本中的甲状腺素（T4）浓度。经过1个月后，未摄食沙隐虫的T4水平与摄食沙隐虫的T4水平无显著差异。因此，沙隐虫的营养状态似乎不会影响其血清T4水平。在变态开始时，血清T4浓度急剧下降，到变态中期（第3阶段）降至产卵成体中观察到的水平（勒卢普和哈迪，1976年；帕卡德等人，1976年）。从第3阶段到变态结束，血清T4水平没有显著变化。文中讨论了血清T4水平下降对七鳃鳗变态事件的可能意义。
