适应高渗环境对两种罗非鱼（莫桑比克罗非鱼和尼罗罗非鱼）血浆及垂体中两种催乳素和生长激素水平的影响。

Effects of acclimation to hypertonic environment on plasma and pituitary levels of two prolactins and growth hormone in two species of tilapia, Oreochromis mossambicus and Oreochromis niloticus.

作者信息

Ayson F G, Kaneko T, Tagawa M, Hasegawa S, Grau E G, Nishioka R S, King D S, Bern H A, Hirano T

机构信息

Ocean Research Institute, University of Tokyo, Japan.

出版信息

Gen Comp Endocrinol. 1993 Jan;89(1):138-48. doi: 10.1006/gcen.1993.1017.

DOI:10.1006/gcen.1993.1017

Abstract

Specific radioimmunoassays (RIAs) for the pair of tilapia prolactins (tPRLs) and growth hormone (tGH) were developed using antisera raised in rabbits. Anti-tPRL177 did not cross-react with tPRL188 and tGH. Anti-tPRL188 did not cross-react with tPRL177 and showed slight cross-reaction (3.1%) with tGH. Anti-tGH showed negligible cross-reactions with tPRL177 (0.4%) and tPRL188 (1.6%). Pituitary homogenates and plasma from Oreochromis niloticus exhibited displacement curves parallel to the standards in the three RIAs. Plasma from hypophysectomized O. niloticus showed no cross-reaction in any of the three RIAs. Plasma and pituitary levels of the two PRLs in O. mossambicus in freshwater did not differ significantly from each other, whereas in O. niloticus, the levels of PRL177 were significantly greater than those of PRL188 in both plasma and pituitary. After acclimation for 3-4 weeks in seawater (O. mossambicus) or 50% seawater (O. niloticus), the levels of both PRLs decreased significantly compared to their levels in freshwater. Acclimation to a hypertonic environment did not affect plasma and pituitary GH levels in either species. Immunocytochemical staining of the pituitary of O. niloticus revealed colocalization of both PRLs in rostral pars distalis. Our findings suggest that the synthesis and secretion of the two tPRLs could be independently regulated in the same cells.

摘要

利用兔抗血清开发了针对一对罗非鱼催乳素（tPRLs）和生长激素（tGH）的特异性放射免疫分析（RIA）方法。抗tPRL177与tPRL188和tGH无交叉反应。抗tPRL188与tPRL177无交叉反应，但与tGH有轻微交叉反应（3.1%）。抗tGH与tPRL177（0.4%）和tPRL188（1.6%）的交叉反应可忽略不计。尼罗罗非鱼的垂体匀浆和血浆在三种RIA中呈现出与标准品平行的置换曲线。垂体切除的尼罗罗非鱼的血浆在三种RIA中均无交叉反应。莫桑比克罗非鱼在淡水中的两种催乳素的血浆和垂体水平彼此无显著差异，而在尼罗罗非鱼中，PRL177在血浆和垂体中的水平均显著高于PRL188。在海水中（莫桑比克罗非鱼）或50%海水中（尼罗罗非鱼）适应3 - 4周后，两种催乳素的水平与淡水中相比均显著下降。适应高渗环境对两种罗非鱼的血浆和垂体生长激素水平均无影响。尼罗罗非鱼垂体的免疫细胞化学染色显示两种催乳素在吻部远侧部共定位。我们的研究结果表明，两种tPRLs的合成和分泌可能在同一细胞中受到独立调节。