Inhibition of in utero galactose-induced cataract development by an aldose reductase inhibitor in rat--electron microscopic study.

The effect of an aldose reductase inhibitor (ARI) on the development of in utero galactose-induced cataract was evaluated by following the morphological changes as seen by light and transmission electron microscope. Pregnant rats were fed a 30% galactose diet until day 17, 18, 19 or 20 of gestation and then given a galactose diet containing ARI. The lenses of newborn rats when mothers were given an ARI diet after day 17, 18 or 19 of gestation showed no morphological change. On the other hand, in the lenses from newborn rats when mothers were given an ARI diet after day 20 of gestation, 30% of those tested showed small vacuoles limited to the posterior cortex, while 70% showed normal structure. When mothers were given a galactose diet during the entire term of pregnancy all lenses of newborn rats showed extensive vacuole formation. ARI was confirmed to completely inhibit congenital galactose cataracts in rats when it was given to the mother rat after day 19 of gestation (ie, on the last 3 days before delivery).