Effect of niravoline (RU51599), a kappa-opioid receptor agonist, on tumour-origin brain oedema

Niravoline is a selective kappa-opioid receptor agonist. Its effect on tumour-origin brain oedema was investigated in a brain tumour model created by implantation of C6 glioma cells into the brain of Wistar rats. Five weeks after the tumour cell implantation, niravoline was administered i.v. at 1 mg/kg, a total of four times at one-hour intervals. In the control group (i.e., saline or vehicle-treated rats), this brain tumour model was found to result in a statistically significant increase in the water content in selected brain regions except for the frontal region, the tumour-containing region and the region surrounding the tumour-containing region. Administration of niravoline inhibited the increase in the water content in the brain regions remote from the tumour.