Perrott M N, Carrick S, Balment R J
Department of Physiological Sciences, School of Biological Sciences, University of Manchester, United Kingdom.
Gen Comp Endocrinol. 1991 Jul;83(1):68-74. doi: 10.1016/0016-6480(91)90106-g.
The role of arginine vasotocin (AVT) in teleostean osmoregulation is unclear. Its administration may produce dose-dependent effects on renal fluid loss though the physiological significance of such effects is unknown due to the paucity of data on the normal range in pituitary and plasma AVT levels. The present study addresses these questions by examining the pituitary AVT activity in the flounder and plasma AVT concentrations in the flounder, trout, and carp following alterations in environmental tonicity. Flounder pituitary AVT content, measured by bioassay, was elevated in freshwater (FW)-acclimated compared to seawater (SW)-acclimated fish and rapidly fell or rose, respectively, following transfer from FW to SW or from SW to FW to attain a new steady state. Plasma levels of AVT were higher in FW than in SW in both flounder and trout and it would, therefore, appear that the synthesis, storage, and secretion of AVT may be enhanced in FW. In the stenohaline carp plasma levels of AVT were unchanged on acclimation from FW to 40% SW. In SW flounder there was a significant positive correlation between plasma osmolality and plasma AVT concentration. Such a relationship was not apparent in FW fish, which may reflect differing roles for the hormone in these two extremes of osmotic environment.
精氨酸加压催产素（AVT）在硬骨鱼渗透压调节中的作用尚不清楚。尽管由于垂体和血浆中AVT水平正常范围的数据匮乏，其生理意义尚不清楚，但给予AVT可能会对肾液流失产生剂量依赖性影响。本研究通过检测环境张力改变后比目鱼的垂体AVT活性以及比目鱼、鳟鱼和鲤鱼的血浆AVT浓度，来解决这些问题。通过生物测定法测得，与适应海水（SW）的比目鱼相比，适应淡水（FW）的比目鱼垂体AVT含量升高，并且在从FW转移到SW或从SW转移到FW后分别迅速下降或上升，以达到新的稳定状态。比目鱼和鳟鱼中，FW中的AVT血浆水平均高于SW，因此似乎在FW中AVT的合成、储存和分泌可能会增强。在狭盐性鲤鱼中，从FW适应到40%SW后，AVT的血浆水平没有变化。在SW比目鱼中，血浆渗透压与血浆AVT浓度之间存在显著正相关。这种关系在FW鱼中并不明显，这可能反映了该激素在这两种极端渗透环境中的不同作用。
