INFLUENCE OF ALDOSE REDUCTASE INHIBITION ON THE MICROVASCULAR REACTIVITY IN EXPERIMENTAL DIABETES

1. To verify if tolrestat, an aldose reductase inhibitor, corrects the impaired responses of microvessels to histamine and bradykinin in all oxan-diabetic rats, the mesenteric microcirculation was studied in viv o in anaesthetised animals. 2. The impaired responses were corrected b y tolrestat 5 mg/kg/day for 7 days p.o. Similar responses to acetylcho line and sodium nitroprusside were obtained in preparations of diabeti c and control rats and were not altered by tolrestat treatment 3. As i n diabetes, galactosemia induced impaired responses to histamine and b radykinin; these altered responses were corrected by tolrestat treatme nt. 4. These data allow us to suggest that the polyol pathway activity might be involved in the altered responses of microvessels observed i n diabetic rats. It is possible that polyol activation may play an imp ortant role in the development of vascular dysfunction in diabetes mel litus.