Synthetic eel calcitonin stimulates thyrotropin releasing hormone release from rat stomach in vitro.

The effect of synthetic eel calcitonin on the release of thyrotropin releasing hormone (TRH) from the rat stomach in vitro was studied. The rat stomach was incubated in medium 199 with 1.0 mg/ml of bacitracin (pH 7.4) for 20 min. The amount of TRH released into the medium was measured by radioimmunoassay. After the addition of synthetic eel calcitonin the release of immunoreactive TRH from the rat stomach in vitro was enhanced significantly in a dose-related manner. Elution profile of acid-methanol-extracted rat stomach on Sephadex G-10 was identical to that of synthetic TRH. The findings suggest that synthetic eel calcitonin stimulated TRH release from the rat stomach in vitro.