Figure 4.
Neuroprotective efficacy of clinical progestins. Rat primary hippocampal neurons were exposed to neurotoxic glutamate 200 μm and the protective effects of progestins determined by LDH release. The neuroprotective effect was defined as NE and calculated as follows: NE = (Vsample − Vglutamate)/(Vcontrol − Vglutamate). Data are presented as the percentage of values produced by vehicle-treated control cultures, and the proliferative efficacy of each progestin (solid line) was compared with that of P4 (dotted line). A–C, Progestins with neuroprotective efficacy comparable with P4. D–F, Clinical progestins with modest neuroprotective efficacy. *, P < 0.05; **, P < 0.01; ***, P < 0.005; and ****, P < 0.001 compared with glutamate-treated cultures.