ATPase activity defects in alloxan-induced diabetic sciatic nerve recovered by ganglioside treatment

ATPase activities were measured in sciatic nerves from rats with alloxan-induced diabetes (ALX-D) of various duration (2 wk, 5 wk, 9 wk, and 6 mo). Our data confirm that sciatic nerve Na+-K+-ATPase abnormalities are present very early in ALX-D rats, similar to results previously described in streptozocin-induced diabetic rats, spontaneously diabetic BB Wistar rats, and ALX-D rabbits. Na+-K+-ATPase activity decreased by 26-47% in ALX-D rats compared with age-matched controls. Ganglioside treatment (10 mg/kg i.p. for 10 or 30 days starting 1 wk after ALX injection) completely impeded the enzyme reduction. The effect observed at the end of either 10 or 30 days of treatment lasted greater than or equal to 1 mo. Chronic diabetic groups treated for 30 days before killing also presented normal ATPase activity at the end of treatment. Therefore, gangliosides are effective on Na+-K+-ATPase even in animals with a longer duration of diabetes. The maintenance of fairly normal ATPase activity by ganglioside treatment could mirror a more general recovery from early metabolic dysfunction and/or late structural abnormalities in diabetic nerve fibers.