Ammonia excretion by the skin of zebrafish (Danio rerio) larvae

Tin Han Shih, Jiun Lin Horng, Pung Pung Hwang, Li Yih Lin

Research output: Contribution to journalArticle

98 Citations (Scopus)

Abstract

The mechanism of ammonia excretion in freshwater teleosts is not well understood. In this study, scanning ion-selective electrode technique was applied to measure H+ and NH4+ fluxes in specific cells on the skin of zebrafish larvae. NH4+ extrusion was relatively high in H+ pump-rich cells, which were identified as the H+-secreting ionocyte in zebrafish. Minor NH 4+ extrusion was also detected in keratinocytes and other types of ionocytes in larval skin. NH4+ extrusion from the skin was tightly linked to acid secretion. Increases in the external pH and buffer concentration (5 mM MOPS) diminished H+ and NH 4+ gradients at the larval surface. Moreover, coupled decreases in NH4+ and H+ extrusion were found in larvae treated with an H+-pump inhibitor (bafilomycin A1) or H+-pump gene (atp6v1a) knockdown. Knockdown of Rhcg1 with morpholino-oligonucleotides also decreased NH4+ excretion. This study demonstrates ammonia excretion in epithelial cells of larval skin through an acid-trapping mechanism, and it provides direct evidence for the involvement of the H+ pump and an Rh glycoprotein (Rhcg1) in ammonia excretion.

Original languageEnglish
JournalAmerican Journal of Physiology - Cell Physiology
Volume295
Issue number6
DOIs
Publication statusPublished - Dec 2008
Externally publishedYes

Fingerprint

Proton Pumps
Zebrafish
Ammonia
Larva
Skin
Gene Knockdown Techniques
Ion-Selective Electrodes
Morpholinos
Acids
Fresh Water
Keratinocytes
Glycoproteins
Buffers
Epithelial Cells

Keywords

  • Ammonium
  • H-adenosine 5′-triphosphatase
  • Ion-selective electrode
  • Ionocytes
  • Knockdown
  • Rhesus glycoprotein

ASJC Scopus subject areas

  • Cell Biology
  • Physiology

Cite this

Ammonia excretion by the skin of zebrafish (Danio rerio) larvae. / Shih, Tin Han; Horng, Jiun Lin; Hwang, Pung Pung; Lin, Li Yih.

In: American Journal of Physiology - Cell Physiology, Vol. 295, No. 6, 12.2008.

Research output: Contribution to journalArticle

@article{7f0d8ad75eb74fd3bdc59c2bb7aa0254,
title = "Ammonia excretion by the skin of zebrafish (Danio rerio) larvae",
abstract = "The mechanism of ammonia excretion in freshwater teleosts is not well understood. In this study, scanning ion-selective electrode technique was applied to measure H+ and NH4+ fluxes in specific cells on the skin of zebrafish larvae. NH4+ extrusion was relatively high in H+ pump-rich cells, which were identified as the H+-secreting ionocyte in zebrafish. Minor NH 4+ extrusion was also detected in keratinocytes and other types of ionocytes in larval skin. NH4+ extrusion from the skin was tightly linked to acid secretion. Increases in the external pH and buffer concentration (5 mM MOPS) diminished H+ and NH 4+ gradients at the larval surface. Moreover, coupled decreases in NH4+ and H+ extrusion were found in larvae treated with an H+-pump inhibitor (bafilomycin A1) or H+-pump gene (atp6v1a) knockdown. Knockdown of Rhcg1 with morpholino-oligonucleotides also decreased NH4+ excretion. This study demonstrates ammonia excretion in epithelial cells of larval skin through an acid-trapping mechanism, and it provides direct evidence for the involvement of the H+ pump and an Rh glycoprotein (Rhcg1) in ammonia excretion.",
keywords = "Ammonium, H-adenosine 5′-triphosphatase, Ion-selective electrode, Ionocytes, Knockdown, Rhesus glycoprotein",
author = "Shih, {Tin Han} and Horng, {Jiun Lin} and Hwang, {Pung Pung} and Lin, {Li Yih}",
year = "2008",
month = "12",
doi = "10.1152/ajpcell.00255.2008",
language = "English",
volume = "295",
journal = "American Journal of Physiology",
issn = "0363-6143",
publisher = "American Physiological Society",
number = "6",

}

TY - JOUR

T1 - Ammonia excretion by the skin of zebrafish (Danio rerio) larvae

AU - Shih, Tin Han

AU - Horng, Jiun Lin

AU - Hwang, Pung Pung

AU - Lin, Li Yih

PY - 2008/12

Y1 - 2008/12

N2 - The mechanism of ammonia excretion in freshwater teleosts is not well understood. In this study, scanning ion-selective electrode technique was applied to measure H+ and NH4+ fluxes in specific cells on the skin of zebrafish larvae. NH4+ extrusion was relatively high in H+ pump-rich cells, which were identified as the H+-secreting ionocyte in zebrafish. Minor NH 4+ extrusion was also detected in keratinocytes and other types of ionocytes in larval skin. NH4+ extrusion from the skin was tightly linked to acid secretion. Increases in the external pH and buffer concentration (5 mM MOPS) diminished H+ and NH 4+ gradients at the larval surface. Moreover, coupled decreases in NH4+ and H+ extrusion were found in larvae treated with an H+-pump inhibitor (bafilomycin A1) or H+-pump gene (atp6v1a) knockdown. Knockdown of Rhcg1 with morpholino-oligonucleotides also decreased NH4+ excretion. This study demonstrates ammonia excretion in epithelial cells of larval skin through an acid-trapping mechanism, and it provides direct evidence for the involvement of the H+ pump and an Rh glycoprotein (Rhcg1) in ammonia excretion.

AB - The mechanism of ammonia excretion in freshwater teleosts is not well understood. In this study, scanning ion-selective electrode technique was applied to measure H+ and NH4+ fluxes in specific cells on the skin of zebrafish larvae. NH4+ extrusion was relatively high in H+ pump-rich cells, which were identified as the H+-secreting ionocyte in zebrafish. Minor NH 4+ extrusion was also detected in keratinocytes and other types of ionocytes in larval skin. NH4+ extrusion from the skin was tightly linked to acid secretion. Increases in the external pH and buffer concentration (5 mM MOPS) diminished H+ and NH 4+ gradients at the larval surface. Moreover, coupled decreases in NH4+ and H+ extrusion were found in larvae treated with an H+-pump inhibitor (bafilomycin A1) or H+-pump gene (atp6v1a) knockdown. Knockdown of Rhcg1 with morpholino-oligonucleotides also decreased NH4+ excretion. This study demonstrates ammonia excretion in epithelial cells of larval skin through an acid-trapping mechanism, and it provides direct evidence for the involvement of the H+ pump and an Rh glycoprotein (Rhcg1) in ammonia excretion.

KW - Ammonium

KW - H-adenosine 5′-triphosphatase

KW - Ion-selective electrode

KW - Ionocytes

KW - Knockdown

KW - Rhesus glycoprotein

UR - http://www.scopus.com/inward/record.url?scp=57349200569&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=57349200569&partnerID=8YFLogxK

U2 - 10.1152/ajpcell.00255.2008

DO - 10.1152/ajpcell.00255.2008

M3 - Article

C2 - 18815227

AN - SCOPUS:57349200569

VL - 295

JO - American Journal of Physiology

JF - American Journal of Physiology

SN - 0363-6143

IS - 6

ER -