“In the present study we show that in Fura 2 loaded GH4C1 cells, caffeine inhibited, in a dose-dependent manner, the Ca2+ response induced by a submaximally effective dose (3 nM) of thyrotropin-releasing hormone (TRH).”
“Thus, caffeine inhibited the TRH-evoked increase in [Ca2+]i by inhibiting the binding of TRH to its receptor.”