Figure 10. Density of delayed rectifier currents is not significantly reduced by chronic administration of 17β-oestradiol.

Delayed rectifier currents (isolated by application of 4-AP; 5 mm) were recorded from colonic myocytes of ovariectomized females which had received injections of either saline (OVX; A) or 17β-oestradiol (OES; B). 4-AP-insensitive currents were also recorded from non-pregnant females (Female; C). In these conditions, current densities from saline or 17b-oestradiol-treated OVX mice were not significantly different at any voltage tested (D) and there was no change in either the voltage dependence of activation or inactivation with oestradiol administration (F). The density of delayed rectifier currents was significantly lower for non-pregnant females compared with oestradiol-treated OVX females through a wide range of voltages tested (E).