[Effects of methylprednisolone on tumor-induced brain edema]

Local cerebral blood flow (LCBF), local cerebral glucose utilization (LCGU) and capillary permeability were studied in rats with tumor-induced brain edema. Moreover, effects of methylprednisolone on these physiological parameters were studied to analyse a possible role of steroid on treatment of peritumoral brain edema. A cubic millimeter pellet of Walker 256 tumor was transplanted to the left sensorimotor cortex of the rat brain. Animals were randomly divided into two groups. One group was treated with methylprednisolone (15 mg/kg/day) for 5 days starting at 5 days after tumor inoculation, and the other group received no treatment. These rats were used for autoradiographic study at 10 days after tumor inoculation. Local CBF, LCGU and capillary permeability were measured with 14C-iodoantipyrine, 14C-deoxyglucose and 14C-alphaaminoisobutyric acid, respectively. In the untreated group, LCBF and LCGU were widely depressed in the cortex and deep structures of the hemisphere ipsilateral to the tumor. Of the methylprednisolone treated animals LCBF and LCGU were significantly better than that of untreated animals. Capillary permeability of the untreated animals were highly increased in the viable part of the tumor. Some increase was also noted in the peripheral edge of the tumor and adjacent brain. In the methylprednisolone treated groups, capillary permeability was significantly lower than that in untreated group. The data suggest that methylprednisolone decreases capillary permeability in the viable part of the tumor.(ABSTRACT TRUNCATED AT 250 WORDS)