in order to identify the changes in thyroid regulation and function that are responsible for the age-related decline in t4 secretion , we measured the secretory response of the rat pituitary and thyroid glands to thyrotropin-releasing hormone ( trh ) , plasma t1/2 for 125i-rat thyrotropin ( tsh ) , the molecular weight of pituitary tsh , t4 uptake and conversion to t3 by the liver , amount of t4 and t3 in serum and in thyroglobulin , and the thyroid peroxidase concentration .
C0032105
plasma
C0229671
serum