Figure 1.

Detection of glutamate (5 to 20 mM) induced DNA fragmentation (DNA ladder) and its prevention by some equine (10 μM) estrogens. A: Lane: 1 = 1 kb DNA ladder; 2 = control HT22 DNA; 3 = 5 mM glutamate; 4 = 10 mM glutamate; 5 = 20 mM glutamate; 6 = 10 mM glutamate (18 h). B: HT22 cells treated with 10 mM glutamate for 18 h in presence or absence of estrogens. Lane: 1 = 17α-E₂; 2 = control; 3 = 10 mM glutamate; 4 = 17β-E₂; 5 = Eq; 6 = 17β-Eqn; 7 = 17α-Eqn; 8 = Δ⁸-E₁. C: Lane: 1 = 1 kb DNA ladder; 2 = control; 3 = 10 mM glutamate alone; 4 = E₁; 5 = Eqn; 6 = 17β-Eq; 7 = 17α-Eq; 8 = Δ⁸,17β-E₂. Gel electrophoresis was carried out as described under methods and the gels were stained with ethidium bromide.