Fig. 3.
Minocycline prevented generation of TNF-α in primary microglia stimulated by LPS (A) or subjected to OGD (B). Microglia were stimulated by 10 µg/ml LPS for 24 h or subjected to 24 h OGD followed by 2 h reperfusion (a paradigm previously shown to cause some microglial death and activation (Yenari & Giffard, 2001)). TNF-α levels were measured in culture supernatants collected at the end of the experiments. In contrast, minocycline did not suppress NO generation, as estimated by the amount of nitrates and nitrated proteins in culture supernatants, in the BV2 microglial cell line (C) or primary microglia (D). Only LPS led to increased NO production, but this was not decreased by minocycline in a concentration found to be neuroprotective. (*P<0.001).