Stimulation of coho salmon growth by insulin-like growth factor I.
The effect of insulin-like growth factor I on growth rate of coho salmon (Oncorhynchus kisutch) was examined. Juvenile coho salmon received implants of osmotic minipumps containing recombinant bovine insulin-like growth factor I (rbIGF-I) or saline for a period of 3 to 4 weeks. High doses of rbIGF-I (greater than 0.13 microgram.g-1.d-1) resulted in hypoglycemia and death. In 2-year-old coho salmon, 0.09 microgram.g-1.d-1 rbIGF-I administered for 25 days doubled linear growth rate and increased growth rate in weight by 40%. In rapidly growing, 1-year-old coho salmon, growth rate was not altered by rbIGF-I at 0.01 or 0.05 micrograms.g-1.d-1 for 31 days. In ration-limited fish exhibiting slow growth in the control group, rbIGF-I (0.02 microgram.g-1.d-1) increased linear growth rate by up to threefold and growth rate in weight by up to fourfold. The results indicate that exogenous treatment with mammalian IGF-I can stimulate coho salmon growth under some conditions, and that endogenous IGF-I may be an important factor in regulating growth of teleosts.
McCormick
S D
SD
Department of Integrative Biology, University of California, Berkeley 94720.
Kelley
K M
KM
Young
G
G
Nishioka
R S
RS
Bern
H A
HA
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001834:Body Water / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002417:Cattle; D004343:Drug Implants; D007334:Insulin-Like Growth Factor I / Q000008:administration & dosage / Q000494:pharmacology*; D007422:Intestines / Q000187:drug effects / Q000254:growth & development; D009929:Organ Size / Q000187:drug effects; D011994:Recombinant Proteins / Q000494:pharmacology; D012474:Salmon / Q000254:growth & development*; D013268:Stimulation, Chemical
D001786:Blood Glucose; D004343:Drug Implants; D011994:Recombinant Proteins; D007334:Insulin-Like Growth Factor I