Figure 10. Adrenaline and noradrenaline enhance I_out only during pregnancy.

Currents were evoked in non-pregnant (NPM) and pregnant (PM) rat uterine myocytes by applying a 200 ms depolarizing pulse every 10 s from -60 to +80 mV. NPM (A) and PM (B) cells were superfused with 10 μM adrenaline (Adr) or 10 μM noradrenaline (Noradr), thereafter 10 μM yohimbine (Yoh) was added. Note that yohimbine disclosed the β-AR-mediated effects of both catecholamines on I_out. Numbers in parentheses denote the number of cells. Cells for each group (Adr and Noradr) in A and B were obtained from five rats. Current densities were used to calculate the percentage values. The pipette solution contained 0.3 μM Ca²⁺. *P < 0.05; **P < 0.01; ***P < 0.001 versus control.