Hasegawa S, Hirano T, Kawauchi H
Gen Comp Endocrinol. 1986 Aug;63(2):309-17. doi: 10.1016/0016-6480(86)90169-3.
Sodium-retaining activity of chum salmon prolactin (PRL) was examined in several euryhaline teleosts. Chum PRL was 100 times more potent than ovine PRL in maintaining plasma sodium levels in the hypophysectomized killifish, Fundulus heteroclitus, transferred from 50% seawater to fresh water. The effects of PRLs were parabolic, high doses of the hormones being less effective than low doses. When injected into seawater-adapted fry of the ayu, Plecoglossus altivelis, or into juvenile rainbow trout, Salmo gairdneri, adapted to 50% seawater, a dose-dependent increase in plasma sodium was observed. Chum PRL was 2-10 times more active than ovine PRL, and the effects in the ayu were also parabolic. An increase in plasma sodium also occurred when the PRLs were injected into the seawater-adapted eel, Anguilla japonica; the chum and ovine PRLs were equipotent, and hypercalcemia was also observed. In contrast, both chum and ovine PRLs were without effect on plasma sodium levels of chum salmon fry, either when injected into seawater-adapted fish kept in seawater or into fish subsequently transferred to fresh water. The absence of an effect of PRLs in chum salmon fry seems to be due, at least in part, to their good osmoregulatory ability during the period of seaward migration; effects of the exogenously administered PRLs may be compensated for by other hormones responsible for their hydromineral balance.
在几种广盐性硬骨鱼中检测了大麻哈鱼催乳素（PRL）的保钠活性。在从50%海水转移到淡水的垂体切除的底鳉（Fundulus heteroclitus）中，大麻哈鱼PRL在维持血浆钠水平方面的效力比绵羊PRL高100倍。PRL的作用呈抛物线形，高剂量激素的效果不如低剂量。当注射到海水适应的香鱼（Plecoglossus altivelis）幼鱼或适应50%海水的虹鳟（Salmo gairdneri）幼鱼中时，观察到血浆钠呈剂量依赖性增加。大麻哈鱼PRL的活性比绵羊PRL高2至10倍，在香鱼中的作用也呈抛物线形。当将PRL注射到海水适应的日本鳗鲡（Anguilla japonica）中时，血浆钠也会增加；大麻哈鱼和绵羊PRL的效力相当，同时还观察到高钙血症。相比之下，无论是注射到饲养在海水中的海水适应的大麻哈鱼幼鱼中，还是注射到随后转移到淡水中的鱼中，大麻哈鱼和绵羊PRL对大麻哈鱼幼鱼的血浆钠水平均无影响。大麻哈鱼幼鱼中PRL无作用似乎至少部分是由于它们在向海洄游期间具有良好的渗透调节能力；外源性施用的PRL的作用可能会被负责其水盐平衡的其他激素所补偿。
