[Effect of prolonged administration of the adrenergic blockaders, fentolamin and obsidan, on the course of alloxan diabetes in rats].

Administration of phentholamine or obsidan to rats for 3 weeks sharply diminished the diabetogenic action of alloxan. The insular tissue of the pancreas became less affected, and the percentage of animals with signs of diabetes (polyuria, glucosuria, and hyperglycemia) decreased. Hyperglycemia (averaging 276 and 286 mg%) was revealed in the majority of the animals given alloxan and adrenoblockers. Phentholamine sharply suppressed the development of polyuria in rats with intact pancreas following water load, but obsidan produced no such effect. The mechanism of action of adrenoblockers used on polyuria and glucosuria in animals given alloxan is suggested on the basis of experiments with water load.