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

January 1, 1991

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 adaptation of salmonids.

Publication Year 1991
Title Osmoregulatory actions of insulin-like growth factor-I in rainbow trout (Oncorhynchus mykiss)
DOI 10.1677/joe.0.1300087
Authors S. D. McCormick, T. Sakamoto, S. Hasegawa, T. Hirano
Publication Type Article
Publication Subtype Journal Article
Series Title Journal of Endocrinology
Index ID 1014565
Record Source USGS Publications Warehouse
USGS Organization Leetown Science Center