Streptozotocin-produced cataracts in rats.

S, 'treptozotocin, an antibiotic produced from Streptomyces achromogenes, is now being used frequently for the production of experimental cataract." The exact mechanism of this cataract formation has not yet been determined. Streptozotocin has two distinct properties, either of which it was considered could be responsible for the cataract formation. First, Streptozotocin possesses the property of selective destruction of the beta cells of the pancreas in monkeys, dogs, and rodents, producing diabetes mellitus. Second, Streptozotocin possesses antimitotic properties when used in rats and mice with lymphoid leukemia. To investigate which of these properties might be responsible for the cataract formation, nicotinamide was used in the experiment described below. Nicotinamide has been found to protect rats against the pancreolytic effect of Streptozotocin but to have no action on its antitumor properties.