1. The hemolytic effect of
L-sorbose on canine erythrocytes characterized by inherited high Na, K-
ATPase activity and a high
potassium concentration (HK RBCs) was compared with that on normal canine erythrocytes (LK RBCs). 2. Dogs having HK RBCs (HK dogs) revealed no clinical and hematological changes after administration of
L-sorbose, whereas normal dogs (LK dogs) developed severe
hemolytic anemia associated with
hemoglobinuria and marked decreases of erythrocyte
ATP concentrations. 3. In vitro,
L-sorbose induced
hemolysis in LK RBCs along with the depression of both
ATP and
lactate formation in these cells, but not in HK RBCs. The inhibition of glycolysis by
L-sorbose in LK RBCs, however, was not observed when
glucose-6-phosphate was used as a substrate instead of
glucose. 4. These results suggest that the disparity of susceptibility to
sorbose-induced
hemolysis may be due to the difference in erythrocyte metabolism between HK and LK RBCs, especially the high activity of
hexokinase in HK cells, which was 2-fold greater than that in LK RBCs.