Modification of the effect of dimethyl sulfoxide on intracranial pressure, brain water, and electrolyte content by indomethacin.

Albino rabbits with experimental brain oedema produced by a combined cryogenic left hemisphere and a metabolic 6-aminonicotinamide lesion were given indomethacin (20 mg/kg) fifteen minutes prior to dimethyl sulfoxide (DMSO) treatment (1 g/kg bolus). Intracranial pressure (ICP), systolic arterial pressure (SAP), central venous pressure (CVP), and EEG were continuously measured while the animals were being mechanically ventilated at a constant PaCO2 (38-42 torr). At the end of the run, brain H2O and electrolytes were measured. There was no significant reduction in ICP at 5 minutes and 15 minutes after DMSO. This was strikingly different to what occurred when DMSO alone was administered, when a significant reduction was noted (p less than 0.05). At 30 minutes there was a reduction in ICP in both the DMSO and the DMSO/indomethacin groups, but in the former it was 50% of the pretreatment values while in the latter it was only 24%. Because indomethacin is a proven prostaglandin inhibitor, these results suggest that these substances may play a role in the mechanism of action of DMSO.