Fig. 3

Combination of β2 adrenergic receptor agonist with ANO-1 blockade enhances relaxation of human uterine smooth muscle in terms of intracellular calcium flux and contractile force. a Representative fura-2 calcium tracings demonstrating that pretreatment with BB or MN in combination with TRB attenuates increase in intracellular calcium induced with oxytocin. BB = benzbromarone, MN = MONNA, TRB = terbutaline. b Average peak of intracellular calcium induced with oxytocin 1 µM after pretreatment demonstrating significant attenuation of intracellular calcium with low dose TRB + BB or TRB + MN versus the BB, MN, or TRB alone groups (***p < 0.001; for BB, MN, and TRB, n = 10 each; for TRB + BB or TRB + MN; n = 14 each). c Representative force tracings showing the enhanced potency of combining low dose TRB and BB (orange tracing) or MN (pink tracing) on both frequency and force of oxytocin-induced contractions compared to single low dose treatments (BB 5 μM: blue, MN 25 μM: red, TRB 0.01 μM: light blue) or vehicle control (black tracing). d Compiled data illustrate percentage of integral force (g*sec) compared to baseline oxytocin-induced contractility between treatment groups. Results were normalized to the control and reported as mean ± SEM. We observed statistically significant potentiation of relaxation with low dose TRB + BB/MN versus control (***p < 0.001; n = 64 samples from 9 different patients)