Cold‐induced changes in circulating levels of catecholamines and thyroid hormones are modulated by energy intake in newborn pigs

Abstract

Newborn pigs were kept at a low ambient temperature from 6 until 54 h of age and supplied with a limited (LI, 415 g (kg body weight)‐1) or a high (HI, 655 g (kg body weight)‐1) intake of milk. At the end of the treatment, both groups had similar deep body temperatures and metabolic rates. However, plasma adrenaline and noradrenaline levels were, respectively, 5.8‐ and 3.0‐fold lower (P < 0.01) in HI than LI piglets, whereas plasma 3,5,3'‐triiodothyronine (T3) was 1.5‐fold higher (P < 0.01) in HI piglets. It is concluded that the hormonal control of cold‐induced thermogenesis is modulated by energy intake, with catecholamines and thyroid hormones acting in a closely related and complementary manner. © 1995 The Physiological Society