Marked Depletion of Plasma 1,5-Anhydroglucitol, a Major Polyol, in Streptozocin-induced Diabetes in Rats and the Effect of Insulin Treatment

Plasma levels of 1,5-anhydroglucitol (1,5AG), a major polyol resembling glucose in structure, fell rapidly and dramatically in streptozocin (STZ)-treated rats. 1,5AG fell immediately after STZ injection, reaching a plasma level 6 h after administration of the drug that was one-third that in the plasma of control rats. Reduction of 1,5AG was independent of the profile of blood glucose induced by STZ. After intravenous injection of [¹⁴C]-1,5AG, its plasma half-life was determined to be between 120 and 180 min. After a phase of acute decrease, the reduction of 1,5AG became gradual, stopping within 6 days after treatment. However, in some cases, the drop in 1,5AG was partially reversible by insulin treatment. The extent to which 1,5AG fell did not strictly correspond to the dose of STZ. The particular organ(s) consuming or accumulating 1,5AG was not identified. However, aside from the large amount of 1,5AG in plasma and the small amount of 1,5AG in the urine, the liver appears to be a significant organ for metabolism Of 1,5AG.