Figure 2.

Effect of NPPC on GLYT1 activation. (a) GLYT1 activity (black circles) was measured as the rate of transport of [³H]-glycine by oocytes isolated from COCs that had been cultured for 4 h as a function of NPPC concentration (0–1 µM) during culture. Increasing NPPC concentration had no significant effect on GLYT1 activity (NS, by ANOVA, P = 0.16). The extent of GVBD in the oocytes used for GLYT1 activity measurements here was previously reported²¹, and are replotted here (gray squares) for reference. Each point represents the mean ± s.e.m. of 3 or 4 independent repeats. (b) Various inhibitors were tested for an effect on the development of GLYT1 activity in oocytes within COCs cultured for 4 h in the presence of NPPC (100 nM) and E₂ (100 nM). As shown in (A), culture with NPPC alone had no significant effect, nor did culture with NPPC and either hypoxanthine (4 mM) and guanosine (50 µM) together (H + G), the PDE9 inhibitor BAY 73-6691(BAY), or all three together. Data were analysed by ANOVA with Tukey test (overall effect: P < 0.0001; between treatments: ***P < 0.001). Each bar represents the mean ± s.e.m. of five independent repeats, except at t = 0 (3 repeats).