In vitro incorporation of [14C]glycine into muscle protein of gulf killifish (Fundulus grandis) in response to insulin-like growth factor-I.
The effect of recombinant human insulin-like growth factor I (rhIGF-I) on protein synthesis was studied in vitro in the muscle of a teleost fish. Protein synthesis was assessed by the incorporation of [14C]glycine into protein. rhIGF-I stimulated [14C]glycine incorporation in a dose-dependent manner. The minimal effective dose was 0.1 ng/ml and maximal stimulation was obtained with 1 ng/ml. A high concentration (100 ng/ml) was ineffective. Treatment with 1 ng/ml rhIGF-I produced a significant response after 3 hr of incubation and the greatest stimulation was observed after 6 hr. Responsiveness of muscle tissue to IGF-I examined at three different times (0, 6, and 12 hr after light onset, LD 12:12) was greatest at light onset. These results provide evidence that IGF-I may have a role in the regulation of growth in fish and that its activities are dose and time-of-day dependent.
Negatu
Z
Z
Department of Zoology and Physiology, Louisiana State University, Baton Rouge 70803, USA.
Meier
A H
AH
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D002250:Carbon Radioisotopes; D002940:Circadian Rhythm / Q000187:drug effects / Q000502:physiology; D003513:Cycloheximide / Q000494:pharmacology; D003609:Dactinomycin / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D005998:Glycine / Q000037:antagonists & inhibitors / Q000493:pharmacokinetics*; D066298:In Vitro Techniques; D007334:Insulin-Like Growth Factor I / Q000494:pharmacology*; D007695:Killifishes / Q000378:metabolism*; D009124:Muscle Proteins / Q000187:drug effects / Q000378:metabolism*; D011994:Recombinant Proteins / Q000494:pharmacology; D014238:Trichloroacetic Acid / Q000378:metabolism
D002250:Carbon Radioisotopes; D009124:Muscle Proteins; D011994:Recombinant Proteins; D003609:Dactinomycin; D014238:Trichloroacetic Acid; D007334:Insulin-Like Growth Factor I; D003513:Cycloheximide; D005998:Glycine