Effect of thyroid hormones from maternal milk on some measures of body growth and endocrine system in newborn sucklings.

The effect of thyroidectomy (TX) in lactating mother on the development of sucklings was studied during first 15 days of life. TX resulted in a decrease of thyroxine (T4) level in maternal milk which further resulted in a decrease of the level of T4, insulin and glucose in serum of newborns, and a decrease of body weight and of the glycogen content in liver. It is suggested that the hypoglycemia, decrease of liver glycogen and retardation of body growth under such conditions result from the inhibition of glucogenesis due to a deficiency of T4 and presumably also of GH in sucklings. These investigations showed that changes of glucose and glycogen in newborns during the early postnatal period together with some other measures of the development may be used in the evaluation of their adaptation capability.