COX-1 inhibition reverses protection obtained by COX-2 inhibition, EP1 receptor deletion, and EP2 receptor activation.

<p>(<b>A</b>) Cortical lesion volumes were determined from thionine stained serial brain sections 24 hours after NMDA injection. Where indicated, animals received NS398 and/or SC560 as described in <i>Methods</i>. Vehicle consisted of 100 µl DMSO∶Saline (1∶9) administered i.p. (n = 6–9/group, * p<0.05). (<b>B</b>) NMDA lesion volumes in EP1^−/− mice systemically treated with vehicle (as in A) or SC560 (n = 5/group, * p<0.05 from vehicle). (<b>C</b>) Mice received the EP2 receptor agonist Butaprost (170 fmol) together with NMDA resulting in reduced lesion volumes. Lesions are enlarged in mice receiving SC560 (vehicle as in A; n = 9/group; * p<0.05 from vehicle). (<b>D</b>) Reduced lesion in nNOS^−/− mice is not reversed by SC560 (n = 6/group; n.s. = non significant).