[Histochemical studies on glycosaminoglycans in Bruch's membrane of experimental microphthalmic mice]

The Cts mouse is a mutant mouse of the Jcl:ICR strain which has congenital cataracts and small eyes in homozygotes. Therefore, this mouse could be a model for autosomal dominant cataract with microphthalmia in humans. In the present study, attempts were made to demonstrate light-microscopically the molecular species of glycosaminoglycans (GAG) in Bruch's membrane of Cts mice on day 14, 16, and 18 of gestation and at 0, 4, and 7 days after birth by means of combined sensitized high iron diamine staining and testicular hyarulonidase digestion procedures. In Bruch's membrane of the unaffected mice at all stages examined, no substantial amount of chondroitin sulfate A/C could be detected. In homozygous mice, however, a large amount of chondroitin sulfate A/C was contained in Bruch's membrane. These results indicate that the abnormal change in GAG molecular species induced the functional disorder of Bruch's membrane and could play a certain role in the etiology of microphthalmia in homozygotes.