The effect of dexamethasone , metronidazole and ascorbic acid on the morphological changes induced by gamma rays on the spinal cord of Wistar rats

Abstract

We studied the effects of dexamethasone, ascorbic acid, and metronidazole on the irradiated spinal cord of Wistar rats. Thirty adult Wistar rats were randomly assigned into 3 groups. Five rats served as the control group. Another group of 5 rats were irradiated in the neural axis with 2.5 Gy of gamma rays. The last group of 20 rats were irradiated and then divided into four subgroups of 5 rats each: one subgroup was administered dexamethasone alone, a second subgroup had metronidazole alone, a third subgroup w a s treated with dexamethasone and metronidazole combined, and a fourth subgroup had ascorbic acid alone, given intraperitoneally for 7 days before exposure to radiation, and also for 5 days after-irradiation. All irradiated animals demonstrated similar vascular changes in form of splitting of the smooth muscle layers of the arterioles of the anterior spinal arteries. Similarly, all the irradiated spinal cord demonstrated shrinkages as noted in the diminution of the neuronal sizes measured by a microscope with a micrometer embedded in the eye-piece objective. The drugs did not individually protect neurons from damage at the level of our investigation. However, the combination of dexamethasone and metronidazole produced a reduction of the degenerative effect of radiation on the neurons when the post-irradiation diameters of the neurons were compared with the control and those of the other experimental groups. We conclude that gamma ray induced damage in the spinal cord may be ameliorated by combining dexamethasone with metronidazole but not by individual treatment with any of the three drugs.