The effects of oxytocin (OT) and oxytocin extended form (OT-GKR) on intracellular calcium levels measured in Fura-2-loaded H9c2 cells.

(A). Percentage of calcium-responsive cells counted per microscopic field after treatment with equimolar concentrations (10⁻⁶ M) of OT and OT-GKR. (B) Kinetics of intracellular calcium levels normalized as the F340/F380 ratio in cells responding to OT-GKR and (C) in cells resistant to OT-GKR Data were obtained from 7 separate experiments. For (A), statistical analysis was performed using a Students t-test. Data are presented as mean ± SEM. ***: p<0.001, compared to OT-GKR-treated cells.