Inhibition of dehydroascorbic acid transport across the rat blood-retinal and -brain barriers in experimental diabetes.
Vitamin C is mainly transported across the blood-retinal and -brain barriers as dehydroascorbic acid (DHA) via a facilitative glucose transporter, GLUT1, and accumulates as ascorbic acid in the retina and brain. To investigate whether DHA transport to the retina and brain is changed by hyperglycemia, [14C]DHA transport across the blood-retinal and -brain barriers was examined using in vivo integration plot analysis in streptozotocin-induced diabetic rats with a 3-week duration of diabetes and in normal rats. Blood-to-retina and -brain transport of [14C]DHA was reduced by 65.5% and 84.1%, respectively, in diabetic rats compared with normal rats, whereas there was no major difference in the heart. Therefore, we propose that hyperglycemia reduces the supply of vitamin C to the retina and brain.
Minamizono
Akito
A
Department of Pharmaceutics, Graduate School of Medical and Pharmaceutical Sciences, University of Toyama, Toyama, Japan.
Tomi
Masatoshi
M
Hosoya
Ken-ichi
K
D000818:Animals; D001692:Biological Transport / Q000187:drug effects; D001812:Blood-Brain Barrier; D001813:Blood-Retinal Barrier; D003683:Dehydroascorbic Acid / Q000493:pharmacokinetics*; D003921:Diabetes Mellitus, Experimental / Q000378:metabolism*; D008297:Male; D051381:Rats; D017208:Rats, Wistar; D013311:Streptozocin
D013311:Streptozocin; D003683:Dehydroascorbic Acid