Figure 4

A comparison of the saturation transfer difference spectra of follicles superfused with Ringer's solution (control, upper spectrum) and Ringer's solution containing inducing levels (3.2 UM) of progesterone (lower spectrum) at 20-22°C. The midpoint of the spectral data aquisition corresponded to a 5.5 h exposure to progesterone. A marked decrease in the γP → PCr saturation transfer effect is observed in progesterone-treated oocytes. Again, the large inverted peaks are due to incomplete cancellation of the overwhelming phosvitin signal.