Fig. 2.
Effect of thyroid-stimulating hormone (TSH): Thyrotropin-releasing hormone (TRH) from the hypothalamus activates the release of TSH from the anterior pituitary which activate the release of thyroid hormones (THs) in a positive feedback loop. Increasing levels of THs inhibit the release of both TRH and TSH in a negative feedback loop. Leptin activates the release of TRH from the hypothalamus; somatostatin (SS) and dopamine (DA) inhibit TSH release from the pituitary. Glucocorticoids and pro-inflammatory cytokines inhibit TSH release
