The effect of acute cold and warm ambient temperatures on the thyroid hormone concentration in blood plasma, blood supply, and oxygen consumption in Japanese quail

Blood supply to the thyroid gland, blood plasma T 4 and T 3 concentration, oxygen consumption, and body temperature were measured in Japanese quail in cold (−1 to −6°) and warm (34 to 35°) ambient temperatures. The most pronounced changes were noted during the first hour of temperature influence. During this time, in cold ambient temperature, the blood supply of the thyroid and T 3 concentration in the plasma increased 2.14- and 3.24-fold, respectively. The T 4 concentration initially decreased significantly then it increased. In a warm ambient temperature constant decreases in blood supply and T 4 concentration were noted. The plasma T 3 concentration was significant greater at 5 and 48 hr after warm exposure. Oxygen consumption was elevated within the first hour of cold diuration, a decline in oxygen consumption was not observed before Hour 12 of heat influence. A statistically significant change in rectal and skin temperatures occurred chiefly during cold exposure.