| Abstract: | The effects of several hormones on the production of immunoreactive serum albumin (SA) were examined in primary cultures of liver cells obtained from rat fetuses on 21-22 days of gestation of from 3-week old rats. Cortisol, bovine insulin and human growth hormone stimulated SA production in both types of liver cell cultures during 20 h-incubation. L-Triiodothyronine (T3; 10(-9)-10(-7) M) weakly stimulated SA production by hepatocytes from the rats, but markedly inhibited it in cultures of fetal rat liver cells in a dose-dependent manner. In contrast, T3 action on total RNA and protein biosynthesis, estimated as the incorporation of labelled precursors into macromolecules, was stimulatory one in both types of cell cultures. It is concluded that hormonal regulation of SA production is similar in cultured liver cells from fetal and early postnatal rats except for the action of T3. The physiological importance of striking developmental change of T3 action on SA production remains to be determined. |
