Fig. 2.

Time- and dose-dependent inhibitory effect of estrogen on brain macrophage activation. (A) The number of ED-1-positive cells in the posterolateral thalamus (PLT) and CA3 was counted in rat brains injected with LPS 6 h after s.c. injection of vehicle (filled bars) or increasing doses of E₂ (0.5, 5, and 50 μg/kg of E₂; dashed bars). (B) Fifty micrograms/kilogram E₂ injected 6 h before (-6h), at the same time as (0), or 2 h after (+2h) LPS. Bars are the average ± SD of a single representative experiment made on three animals; the experiment was repeated three times. Data are calculated as percentage of LPS alone. **, P < 0.01 vs. LPS.