Evidence for a neuroprotective effect of pyrid-3-yl-sulphonyl-urea in photochemically induced focal ischaemia in rats: magnetic resonance imaging evaluation.

A neuroprotective effect can be obtained with N-[(4-cycloheptylaminopyrid-3-yl)sulphonyl]N'-cycloheptyl urea (BM27), a pyrid-3-yl-sulphonylurea structurally related to torasemide, a loop diuretic. We have investigated the neuroprotective effect of BM27 by magnetic resonance imaging and use of the photothrombotic model of cerebral infarction in the rat. This method enables non-invasive quantification of the extent of the cerebral oedema from T2-weighted spin-echo images. This article reports the evolution of the extent of oedema with time (0.5, 1, 2, 4, 6, 24 and 48 h, 7 and 15 days and 1 month after induction of the lesion) in rats pretreated with 5 mg kg(-1) BM27 or an appropriate control. At all times, the rats treated with BM27 had, on average, smaller lesions than control rats (30% decrease between 2 h and 6 h). These results strongly suggest a significant (P < 0.01) but modest neuroprotective effect of BM27 in ischaemic cerebral stroke. Further investigations should be performed to determine if BM27 or its analogues are of clinical interest.