Susceptibility of Different Strains of Rats to Nutritional Cataract

Abstract

Rats from different colonies fed the lactose or galactose cataract producing rations showed variable susceptibility to cataract. The B.C. strain had the highest incidence and the mature cataracts developed in the shortest time of any of the three breeds tested on the 70% lactose ration. The M.S.C. and W. strains showed advanced lens changes but complete opacities developed in only 10 and 9%, respectively, of the rats tested. On the 35% galactose rations the incidence of mature bilateral cataract was 100% in B.C. and M.S.C. strains and slightly less in W. and J.H. strains. The time for cataract to develop was shortest in the B.C. strain. Severity of intestinal disturbances did not correlate with cataractous changes in the lens. Growth was normal on the galactose but slightly retarded on the lactose ration, probably due to the persistent diarrhea in the young rats. Cataract development was more rapid in young rats than in older ones. The age at which animals are started on experimental rations must be kept constant if results are to be consistent.