In vitro release of growth hormone from the pituitary gland of tilapia, Oreochromis mossambicus.

The release of growth hormone from the proximal pars distalis of the tilapia, Oreochromis mossambicus, was significantly stimulated by cortisol (1 microgram/ml) in an in vitro system. Growth hormone released into the medium and remaining in the tissue was measured by densitometry after gel electrophoresis. Neither triiodothyronine (6.7 ng/ml) nor equimolar concentrations of thyroxin altered the release of growth hormone. In combination with cortisol, triiodothyronine did not alter the effect of cortisol alone.