ZFIN ID: ZDB-PUB-140123-30
Angiotensin II promotes Na+ uptake in larval zebrafish, Danio rerio, in acidic and ion-poor water
Kumai, Y., Bernier, N.J., and Perry, S.F.
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.
ABSTRACT

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.

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