The influence of thyroxine and environmental temperature on the specific activity of hepatic malic enzyme in young male chicks

Abstract

1. 1. Hepatic malic enzyme activity in young male chicks maintained on equalized food and water intakes was significantly reduced by intraperitoneal administration with increasing amounts of thyroxine. 2. 2. Temperature had no significant effect on hepatic malic enzyme activity when chicks were maintained on equalized food and water intakes at 17, 21 and 25°C. 3. 3. In one, but not a second experiment, hepatic malic enzyme activity was significantly increased at 29°C compared with the three lower temperatures. This was considered to reflect the degree of adaptation of the birds to this temperature as the length of temperature exposure differed between experiments. 4. 4. It was concluded that no difference in thyroid secretion rate occurred with temperature-adapted birds within the temperature range studied.