Hepatotoxicity of vanadyl sulfate in nondiabetic and streptozotocin-induced diabetic rats.

This study examined the effects of vanadyl sulfate (VOSO4) on the livers of nondiabetic and streptozotocin-induced diabetic rats. Rats were divided into 6 groups. Groups 1, 2, and 3 consisted of nondiabetic rats that were, respectively, control animals or those receiving an intraperitoneal (i.p.) injection of either 5 or 10 mg·kg-1 (i.p.) VOSO4 for 30 days. Groups 4, 5, and 6 consisted of diabetic animals that were, respectively, control animals or those treated with 5 or 10 mg·kg-1 (i.p.) VOSO4 for 30 days. Results showed that VOSO4 reduced body mass in nondiabetic rats, whereas it increased body mass in diabetic groups. Plasma transaminases (aspartate aminotransferase, alanine aminotransferase), lactate dehydrogenase, and alkaline phosphatase activities and malondialdehyde levels were increased, while liver catalase and superoxide dismutase activities were profoundly decreased in diabetic animals in comparison with enzyme activities in the nondiabetic group. Rats in the diabetic group also showed notable oxidative damage to the liver. Treatment of diabetic rats with VOSO4 decreased the hepatotoxic markers, significantly restored the activities of antioxidant enzymes, and attenuated histopathological changes in liver tissue. In nondiabetic rats, VOSO4 treatment increased most of the hepatotoxic markers, reduced antioxidant enzyme activities, and induced pronounced oxidative damage in liver tissue. These data suggest that treatment with VOSO4 exerts toxic effects in healthy animals and significantly prevents liver oxidative damage in streptozotocin-induced diabetic rats, but without total safety. Further studies are needed to clarify its mechanism of action.

Effects of acute exposure to static magnetic field on ionic composition of rat spinal cord.

The purpose of this study is to evaluate the effect of static magnetic fields (SMF) on ionic composition of rat spinal cord. Male Wistar rats were daily exposed to SMF of 128 mT, for 1 h/day during five consecutive days. Spinal cord samples were extracted, weighed and mixed in bidstilled water in order to be analyzed by inductively coupled plasma (ICP). Plasma ionic composition was also made. Acute exposure to SMF increased significantly the calcium (+68%, p < 0.05) and iron (+35%, p < 0.05) contents of rat spinal cord, whereas magnesium and copper levels remained unchanged. In plasma, SMF treatment failed to alter calcium concentration but decreased iron level (-17%, p < 0.05). These data indicate that SMF acute exposure can induce alterations of ionic composition in the rat spinal cord and the plasma electrolytes balance.