RT3 then is inhibiting the increase in metabolism or the calorigenic
effect of thyroid hormone.
In animal studies, it was observed that the effect of caffeine was partly due to endogenous catecholamine release and partly to the intrinsic calorigenic
effect on diet on the grass shrimp Crangon franciscorum (Crustacea: Crangonidae).
34) Reports have indicated that thyroid hormones exert their positive calorigenic
actions and augmented oxygen demands by increasing the activity and the numbers of the mitochondria in tissues like skeletal muscle, heart, kidney, and liver.
Food preferences are influenced by calorigenic
value (Mathur et al.
Metabolic aspects of the calorigenic
effect of thyroid hormone in mammals.
1) T3 exerts significant action on energy metabolism, with the mitochondria being the major target for its calorigenic
(increasing production of energy/heat and oxygen consumption) effects.
18,19) Meticulous studies, however, revealed that the calorigenic
effect of synthetic thyroxine was less than that of thyroid extracts.
This increase can be correlated to the calorigenic
effect induced by the food in the digestive gland.