Influence of mast cells on thyroid function.

: The role of mast cells on thyroid gland function was studied with respect to two sites of thyroid control: 1. the thyroid gland; 2. the hypothalamus pituitary system. It was observed that the treatment with disodium cromoglycate (mast cells stabilizer) partially blocked the TSH actions on thyroid gland, thus evidencing the thyroidal mast cells as an intermediary factor of TSH actions on thyroid gland. Furthermore, both T4 and T3 serum concentrations were increased after compound BW48-80 (mast cells disrupter polymer) was administered, concomitantly with increased 1 and 24 h radioiodine uptake, T/S ratio, PB131I and TSH serum concentration. The alterations were not observed in the rats pre-treated with disodium cromoglycate and administered with BW48-80. Finally, BW48-80 promoted an elevation of TSH serum concentration in T4-primed thyroidectomized rats. This phenomenon was completely prevented by the pretreatment with cromoglycate, which confirmed the active participation of mast cells on TRH and/or TSH secretion.