Kaiya H, Takei Y
Ocean Research Institute, University of Tokyo, Japan.
Gen Comp Endocrinol. 1996 Dec;104(3):337-45. doi: 10.1006/gcen.1996.0179.
Changes in plasma atrial and ventricular natriuretic peptide (ANP and VNP) concentrations were examined in conscious eels, Anguilla japonica, after transfer from freshwater (FW) to seawater (SW) or vice versa. These changes were compared in ventral and dorsal aortic blood since clearance receptors are present in the gills. Plasma Na concentration and osmolality in the ventral aortic blood rose linearly after transfer of FW eels to SW. Six hours after transfer, plasma ANP levels increased from 28.1 +/- 2.9 to 44.8 +/- 5.4 fmol/ml (n = 6) (P < 0.05) and plasma VNP levels also increased from 63.6 +/- 3.8 to 91.2 +/- 6.2 fmol/ml (n = 6) (P < 0.05). However, the levels gradually returned to the FW levels despite plasma Na concentration and osmolality remaining elevated. Dorsal aotic plasma ANP and VNP levels were unchanged after transfer of FW eels to SW, possibly due to extraction of secreted peptides by the branchial clearance receptors. After transfer of SW-adapted eels to FW, plasma ANP and VNP levels were unchanged, while both plasma Na concentration and osmolality decreased. These results indicate that plasma ANP and VNP levels are increased by an increase in plasma Na concentration or osmolality after transfer of FW eels to SW. However, the sustained increase in plasma Na concentration or osmolality no longer stimulated ANP and VNP secretion, and plasma ANP and VNP levels gradually returned to the FW levels gradually on adaptation to SW.
在将日本鳗鲡从淡水（FW）转移至海水（SW）或反之之后，检测了清醒状态下的鳗鱼血浆心房和心室利钠肽（ANP和VNP）浓度的变化。由于鳃中存在清除受体，因此对腹主动脉和背主动脉血液中的这些变化进行了比较。将淡水鳗鱼转移至海水后，腹主动脉血液中的血浆钠浓度和渗透压呈线性上升。转移6小时后，血浆ANP水平从28.1±2.9升高至44.8±5.4 fmol/ml（n = 6）（P < 0.05），血浆VNP水平也从63.6±3.8升高至91.2±6.2 fmol/ml（n = 6）（P < 0.05）。然而，尽管血浆钠浓度和渗透压仍保持升高，但这些水平逐渐恢复至淡水水平。将淡水鳗鱼转移至海水后，背主动脉血浆ANP和VNP水平未发生变化，这可能是由于鳃清除受体对分泌肽的提取所致。将适应海水的鳗鱼转移至淡水后，血浆ANP和VNP水平未发生变化，而血浆钠浓度和渗透压均降低。这些结果表明，将淡水鳗鱼转移至海水后，血浆钠浓度或渗透压的升高会导致血浆ANP和VNP水平升高。然而，血浆钠浓度或渗透压的持续升高不再刺激ANP和VNP分泌，并且在适应海水的过程中，血浆ANP和VNP水平逐渐逐渐恢复至淡水水平。
