[Effects of selenium on the serum glucose and insulin levels in diabetic rats]

We investigated the effects of selenium (Se) on the serum glucose and insulin levels in rats with diabetes induced by streptozotocin (STZ, 75 mg/kg, i.p.) and pancreatectomized rats. Moreover, the direct action of Se on insulin release from the isolated pancreatic islets using a slight diabetic rat was studied. The following results were obtained: 1) Selenite at a dose of 173 micrograms/kg (78.9 micrograms/kg of Se base equivalent) drastically reduced the very high level of serum glucose in acute diabetic rats within 5 to 30 min after treatment. During this time period, the insulin level in the serum showed an increasing tendency. 2) The high serum glucose level in chronic diabetic rats returned to the original level with injection of selenite for 4 days, once a day. However, Se did not elicit a significant increase in serum insulin level. 3) Although there was a tendency for the serum glucose level to decrease when selenite was administered into pancreatectomized rats, no secretion of insulin into the serum was observed. 4) Insulin release from isolated pancreatic islets was dose-dependently accelerated by the addition of selenite. These data present the new finding that Se reduced the high level of serum glucose in diabetic rats.