Attenuation by chlormethiazole of oedema following focal ischaemia in the cerebral cortex of the rat

Abstract

When a photochemically-induced infarct was produced in the right cortex of rats, tissue water content was increased markedly 4 and 24 h later (control: 79.00 ± 0.08% ischaemia, 24 h: 82.96 ± 0.15%). The left cortex was unaffected. Chlormethiazole (200 mg/kg i.p.) injection 5 min after onset of ischaemia decreased the oedema (ischaemia/chlormethiazole, 24 h: 82.16 ± 0.21%, P < 0.01). At 24 h, ischaemic tissue Na + content was increased (61%) and the K + content decreased (9%). The Na + K + ratio therefore increased significantly ( P < 0.001), a change that was diminished by chlormethiazole administration ( P < 0.02). Chlormethiazole (1 mM), unlike furosemide (5 mM), did not reduce swelling of C6 glioma cells in hypotonic medium. The data suggest that chlormethiazole decreases oedema in this stroke model because of its neuroprotective properties and not because of an effect on anion transport.