Short-term Effects of Hypertonic Shock on Na+K+-ATPase Responses in Gills and Kidneys of the Spotted Green PufferfishTetraodon nigroviridis

摘要

Freshwater (FW) spotted greenpufferfish ( ) could be directly transferred toseawater (SW). This indicated that the spotted green pufferfish possesses an efficientosmoregulatory mechanism to overcome salinity challenges. Although previous studiesexplored osmoregulation in the spotted green pufferfish in FW and SW acclimation, to ourknowledge, no study has addressed short-term time-course changes to elucidate theresponsible mechanism. In the present study, spotted green pufferfish were transferreddirectly from FW to SW. We explored time-course changes in plasma osmolality, and Na andCl concentrations, as well as Na , K -ATPase (NKA) responses (activity and proteinexpression) in gills and kidneys in a short-term (96 h) time-course experiment using thespotted green pufferfish. Plasma osmolality and Cl levels were upregulated within 3 hpost-transfer, and were constant thereafter. Plasma Na concentration responded with arapid increase 6 h post-transfer, and returned to the original level at 48 hpost-transfer. Gills and kidneys are vital osmoregulatory organs, and NKA expressed inthese organs provides the driving force for osmoregulation in euryhaline teleosts. Herein,both branchial and renal NKA responses were modulated soon after SW transfer. BranchialNKA responses including activity and protein abundance of α-subunit were significantlystimulated at 3 h post-transfer; thenceforth were maintained in at a steady state. Incontrast, the activity and protein expression of renal NKA were downregulated at 3 and 12h post-transfer, respectively. The physiological profiles found in this study illustratedhow spotted green pufferfish cope with direct transferred from FW to SW.