Effect of triiodothyronine injection on levels of triiodothyronine and thyroid-stimulating hormone in sera and milk of lactating rats and in sera of their sucklings; precocious development of jejunal alpha-disaccharidases in the sucklings.
Administration of high doses of triiodothyronine (T3) for 4 days to lactating rats evokes an increase in T3 levels in their sera and milk, as well as in the sera of pups suckled by them. Thyroid-stimulating hormone levels in sera of mothers and sucklings are decreased. Suckling rats of T3-treated mothers exhibit a precocious increase in the activity of jejunal sucrase and maltase as well as in activity of several liver acid beta-glycosidases.