Abstract
The uptake-index technique was used to study the effect of streptozotocin-induced diabetes on transport through the blood-retinal (BRB) and blood-brain barriers (BBB) in rats. Untreated diabetes reduced retinal and cerebral uptake of glucose but had no effect on the uptake of L-leucine. A similar reduction in glucose uptake was achieved by an intravenous infusion of glucose in normal rats. Insulin given 1–4 h before the experiments to diabetic rats normalized both blood-glucose levels and retinal and cerebral glucose uptake in diabetic rats. Experiments in hyperglycemic, normal rats suggested that both the preceding plasma glucose level and the concentration of glucose in the injected bolus influence retinal and cerebral uptake of glucose, and we conclude that competitive inhibition may explain the reduction in glucose uptake observed in untreated diabetes.
Similar content being viewed by others
References
Alm A, Tornquist P (1981) The uptake index method applied to studies on the blood-retinal barrier: I. A methodological study. Acta Physiol Scand 113:73–79
Alm A, Tornquist P, Mäepea O (1981) The uptake index method applied to studies on the blood-retinal barrier: II. Transport of several hexoses by a common carrier. Acta Physiol Scand 113:81–84
Braun LD, Miller LP, Pardridge WM, Oldendorf WH (1985) Kinetics of regional blood-brain barrier glucose transport and cerebral blood flow determined with the carotid injection technique in conscious rats. J Neurochem 44:911–915
DiMattio J, Zadunaisky JA, Altzuler N (1984) Onset of changes in glucose transport across ocular barriers in streptozotocin-induced diabetes. Invest Ophthalmol Vis Sci 25:820–826
Ennis SR, Johnson JE, Pander EL (1982) In situ kinetics of glucose transport across the blood-retinal barrier in normal rats and rats with streptozotocin-induced diabetes. Invest Ophthalmol Vis Sci 23:447–456
Gjedde A, Crone C (1981) Blood-brain glucose transfer: repression in chronic hyperglycemia. Science 214:456–457
Harries M, Prom BJ (1970) Relative hypoglycemia. Lancet II:317
McCall AL, Millington WR, Wurtman RJ (1982) Metabolic fuel and amino acid transport into brain in experimental diabetes mellitus. Proc Nall Acad Sci USA 79:5406–5410
Oldendorf WH (1970) Measurement of brain uptake of radiolabeled substances using tritiated water as internal standard. Brain Res 24:372–376
Pardridge WM, Oldendorf WH (1975) Kinetics of blood-brain barrier transport of hexoses. Biochim Biophys Acta 382:377–392
Pardridge WM, Oldendorf WH (1977) Transport of metabolic substrates through the blood-brain barrier. J Neurochem 28:5–12
Tornquist P, Alm A (1986) Carrier-mediated transport of amino acids through the blood-retinal and blood-brain barriers. A study with the uptake index method. Graefe's Arch Clin Exp Ophthalmol 224:21–25
Author information
Authors and Affiliations
Additional information
This study was supported by grant B87-04X-05655-07C from the Swedish Medical Research Council and by a grant from Svenska Diabetesförbundet
Rights and permissions
About this article
Cite this article
Taarnhöj, J., Alm, A. The effect of diabetes on transport through the blood-retinal and blood-brain barriers in rats. Graefe's Arch Clin Exp Ophthalmol 229, 291–293 (1991). https://doi.org/10.1007/BF00167887
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00167887