Osmoregulatory actions of insulin-like growth factor-I in rainbow trout (Oncorhynchus mykiss)

S. D. McCormick, T. Sakamoto, S. Hasegawa, T. Hirano

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42 Citations (Scopus)


The ability of insulin-like growth factor-I (IGF-I), insulin and GH to promote hypoosmoregulatory ability was examined in juvenile rainbow trout (Oncorhynchus mykiss). Following adaptation to 12 parts per thousand (p.p.t.) seawater for 5 days, fish were given a single injection of hormone or vehicle, then exposed to 29 p.p.t. for 24 h and examined for changes in plasma osmolarity, ions and glucose. Ovine GH (oGH; 0.2 μg/g) significantly improved the ability of rainbow trout to maintain plasma osmolarity and sodium levels following transfer to 29 p.p.t. seawater. Recombinant bovine IGF-I (0.01, 0.05 and 0.2 μg/g) also improved the hypoosmoregulatory ability of trout; the effect being dose-dependent and greater than that of oGH. Bovine insulin (0.01, 0.05 and 0.2 μg/g) had no statistically significant effect on plasma ions. The results indicate that IGF-I is a potential mediator of the action of GH in seawater

Original languageEnglish
Pages (from-to)87-92
Number of pages6
JournalJournal of Endocrinology
Issue number1
Publication statusPublished - 1991
Externally publishedYes

ASJC Scopus subject areas

  • Endocrinology, Diabetes and Metabolism
  • Endocrinology


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