Diabetes Mellitus induces alterations in metallothionein protein expression and metal levels in the testis and liver

OBJECTIVE: To investigate the effect of diabetes with and without vitamin E treatment on testicular metallothionein (MT) and metal (zinc, copper and iron) changes. METHODS: Diabetes was induced with a single intraperitoneal injection (i.p.) of streptozotocin in rats, and diabetic rats were given Vitamin E by i.p. every other day for 4 weeks. MT protein was measured by the cadmium-haeme assay and metal levels were detected by an atomic absorption spectrophotometer. RESULTS: Diabetes did not change testicular MT protein, but significantly increased hepatic MT protein. Diabetes significantly decreased testicular copper, but not hepatic copper. Zinc and iron levels were unchanged in both diabetic testis and liver. Vitamin E significantly enhanced both testicular and hepatic MT, and zinc levels in diabetic rats. Vitamin E slightly decreased the copper levels, but did not change the testicular and hepatic iron in diabetic rats. CONCLUSIONS: Testicular MT protein expression was not increased, even though hepatic MT significantly increased independent of metal changes, in diabetic rats. Vitamin E enhanced testicular and hepatic MT, which correlated with increased zinc levels.