Induction of tyrosine aminotransferase by triamcinolone during rat liver development in vitro

Embryonic rat liver 12–21 days old exhibits low but significant tyrosine aminotransferase (TAT) activity. In organ culture for 24 hr in a nutrient medium, there is an increase in TAT levels. Addition of glucocorticoids increases TAT levels at all embryonic ages. The magnitude of the produced TAT level increases with developmental age. Glucagon also increases embryonic liver TAT, but insulin and growth hormone (somatotropin) had little effect.