Effects of thyroparathyroidectomy and of thyroxin and calcitonin on the tissue distribution of twelve elements in the rat

The effects of thyroparathyroidectomy (TPTY) and of replacement therapy using thyroxin (T4) and calcitonin (CT) on the tissue distribution of elements were studied in the rat under semichronic conditions. The elements Na, K, Ca, Mg, Fe, S, P, Rb, Sr, Mn, Cu, and Zn were determined in whole blood, plasma, brain, liver, heart, kidney, skeletal muscle, and bone. TPTY modified concentrations of all elements tested but only small changes were observed for K, Mg, S, and P. The mineral bone composition was slightly modified, 28 d after TPTY, whereas plasma was the most altered. The consequences of TPTY were corrected fairly well by T4 for Na, Cu, Zn, Fe, and S, and by CT for K, P, Rb but with less efficiency for Ca. This study revealed that hormones of the thyroid gland, mainly T4, play an important role in the plasma and tissue balance of elements. It is suggested that T4 participates in tissue fixation of Cu, Zn, and Fe and that CT influences phosphoremia and cellular Ca binding.