tyreotropowy

Tyreotropowy is an adjective used in endocrinology to describe substances or actions that stimulate the thyroid gland to produce thyroid hormones or to promote its growth. The most prominent tyreotropowy agent is tyreotropina, known in English as thyroid-stimulating hormone (TSH), produced by the anterior pituitary. TSH drives the thyroid to synthesize and secrete the hormones trijodothyronine (T3) and thyroxine (T4) and to undergo growth.

Mechanism-wise, TSH binds to the TSH receptor on thyroid follicular cells, activating the adenylate cyclase-cAMP signaling pathway. This results in increased synthesis of thyroglobulin and thyroid peroxidase, enhanced uptake of iodide, and stimulation of hormone synthesis and release. TSH also has a trophic effect, promoting thyroid gland growth.

Regulation of tyreotropowy activity occurs through the hypothalamic-pituitary-thyroid axis. Thyrotropin-releasing hormone (TRH) from the hypothalamus stimulates TSH secretion, while circulating free T3 and T4 exert negative feedback to suppress both TRH and TSH release. Factors such as circadian rhythms, illness, iodine status, and medications can influence TSH levels.

Clinical relevance includes the use of TSH as a key diagnostic marker of thyroid function. Elevated TSH typically indicates primary hypothyroidism, whereas low TSH can reflect hyperthyroidism or central hypothyroidism. The concept of tyreotropowy behavior also encompasses TSH‑like substances. In therapy and diagnostics, recombinant human TSH is used to stimulate the thyroid for imaging or treatment planning.

Etymology: the term derives from Greek roots referring to the thyroid (thyreos) and stimulation (tropo), and in Polish it is the standard descriptor for thyroid-stimulating activity.