Angiotensin II promotes Na+ uptake in larval zebrafish, Danio rerio, in acidic and ion-poor water
- Authors
- Kumai, Y., Bernier, N.J., and Perry, S.F.
- ID
- ZDB-PUB-140123-30
- Date
- 2014
- Source
- The Journal of endocrinology 220(3): 195-205 (Journal)
- Registered Authors
- Perry, Steve F.
- Keywords
- none
- MeSH Terms
-
- Angiotensin II/metabolism*
- Animals
- Biological Transport
- Larva/genetics
- Larva/growth & development
- Larva/metabolism
- Renin-Angiotensin System
- Sodium/metabolism*
- Solute Carrier Family 12, Member 3/genetics
- Solute Carrier Family 12, Member 3/metabolism
- Up-Regulation
- Water/chemistry*
- Zebrafish/genetics
- Zebrafish/growth & development
- Zebrafish/metabolism*
- Zebrafish Proteins/genetics
- Zebrafish Proteins/metabolism
- PubMed
- 24301614 Full text @ J. Endocrinol.
The contribution of the renin-angiotensin system (RAS) to Na+ uptake was investigated in larval zebrafish (Danio rerio). At 4 days post fertilization (dpf), the whole body angiotensin-II (ANG-II) level was significantly increased after 1- or 3-h exposure to acidic (pH = 4.0) or ion-poor water (20-fold dilution of Ottawa tapwater), suggesting rapid activation of the RAS. Longer (24 h) treatment of 3 dpf larvae with ANG-I or ANG-II significantly increased Na+ uptake which was accompanied by an increase in mRNA expression of the Na+-Cl- co-transporter (zslc12a10.2). Induction of Na+ uptake by exposure to ANG-I was blocked by simultaneously treating larvae with lisinopril (an angiotensin converting enzyme inhibitor). Acute (2 h) exposure to acidic water or ion-poor water led to significant increases in Na+ uptake which were partially blocked by the ANG-II receptor antagonist, telmisartan. Consistent with these data, translational gene knockdown of renin prevented the stimulation of Na+ uptake following exposure to acidic or ion- poor water. The lack of any effects of pharmacological inhibition (using RU486) or gene knockdown of glucocorticoid receptors on the stimulation of Na+ uptake during acute exposure to acidic or ion-poor environments, suggest that the acute effects of RAS occur independently of cortisol signaling. The results of this study demonstrate that the RAS is involved in Na+ homeostasis in larval zebrafish.