Prolactin-releasing peptide is essential to maintain the prolactin level and osmotic balance in freshwater teleost fish

Masaaki Fujimoto, Tatsuya Sakamoto, Tomokazu Kanetoh, Michiyo Osaka, Shunsuke Moriyama

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18 Citations (Scopus)


We administered prolactin-releasing peptide (PrRP) or anti-PrRP antiserum to goldfish in fresh water and analyzed their effects on prolactin and osmoregulatory mechanisms. The pituitary mRNA level of prolactin increased by PrRP but decreased by anti-PrRP. The rate of water inflow in the gills decreased by PrRP and increased by anti-PrRP, showing that PrRP restricts branchial water permeability, as also restricted by prolactin. PrRP also expanded the mucous cell layers on the scales, which may restrict efficiently water inflow by the mucous system. Eventually, the plasma osmotic pressure decreased by anti-PrRP. We conclude that PrRP is essential to maintain prolactin levels and osmotic balance in fresh water.

Original languageEnglish
Pages (from-to)1104-1109
Number of pages6
Issue number5
Publication statusPublished - May 1 2006



  • C-RFa
  • Chloride cells
  • Gills
  • Pituitary
  • PrRP
  • Prolactin
  • mRNA

ASJC Scopus subject areas

  • Biochemistry
  • Physiology
  • Endocrinology
  • Cellular and Molecular Neuroscience

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