Figure 4.

Cyclodextrin binds 5β-reduced potentiating steroids. (a) The effect of γ-cyclodextrin co-applied with a low concentration of 3α5βP (0.3 μM). (b) The effect of γ-cyclodextrin at a saturating concentration of 30 μM 3α5βP. (c) The concentration–response curve of 3α5βP was obtained in the presence and absence of 0.5 mM γ-cyclodextrin. The lines represent fits of the Hill equation to the averaged data points shown in the figure. Parameters from fits to the Hill equation were maximum response: 16.0-fold (baseline) vs 14.7 fold (cyclodextrin), EC₅₀: 0.5 μM (baseline) vs 10.1 μM (cyclodextrin), Hill co-efficient: 2.3 (baseline) vs 1.4 (cyclodextrin); n=5 oocytes. In statistics performed on individual oocytes (see Results), the difference in Hill coefficient was not statistically significant.