TRH receptor binding in avian pituitary and brain

Abstract The pituitary gland of the domestic fowl binds [ 3 H]-[3-methyl-His 2 ]thyrotropin-releasing hormone ([ 3 H]MeTRH) with properties very similar to those exhibited by mammalian TRH receptors, including affinity ( K D = 4.9 n M ), density of binding sites ( B max = 5.1 pmol/g), and pharmacology for eight TRH analogs. Chicken brain appears to contain similar binding sites, but the level of binding was too low for detailed characterization.