14C-Glycine Uptake by Fish Scales: Refinement of a Growth Index and Effects of a Protein-Synthesis Inhibitor

Publisher Website
Google Scholar
Abstract
In vitro 14C‐glycine uptake by the scales of bluegill Lepomis macrochirus was sensitive to the pH of the incubation medium; maximum uptake occurred at approximately pH 7.7. Cycloheximide, an inhibitor of protein synthesis, reduced glycine uptake by up to 90%, providing further evidence for the involvement of glycine uptake in the process of protein synthesis. The minimum duration of handling stress that resulted in a significant change in glycine uptake was 60 minutes; after 240 minutes of continuous stress, glycine uptake was reduced 62% from control values. Diel sampling of laboratory fish indicated no daily rhythm in glycine uptake and demonstrated a significant correlation (r = 0.837) between glycine uptake and fish growth rate as estimated over a 2‐week interval. The results of these experiments suggest that glycine uptake by scales can be a reliable index of fish growth or state of stress. Received December 18, 1982 Accepted June 12, 1983