guanosine-triphosphate and Diabetic-Retinopathy

guanosine-triphosphate has been researched along with Diabetic-Retinopathy* in 1 studies

Other Studies

1 other study(ies) available for guanosine-triphosphate and Diabetic-Retinopathy

ArticleYear
Functional alterations of G-proteins in diabetic rat retina: a possible explanation for the early visual abnormalities in diabetes mellitus.
    Diabetologia, 1992, Volume: 35, Issue:7

    We examined changes in guanosine triphosphate-dependent signal transduction mechanisms in the retina from the early stages of the streptozotocin-diabetic rat, a model for Type 1 (insulin-dependent) diabetes mellitus. Guanosine triphosphate binding, guanosine triphosphatase activity, and binding of (azido) guanosine triphosphate decreased significantly in the retina as early as 2 weeks after the induction of diabetes. The ability of guanosine triphosphate to inhibit forskolin-stimulatable adenyl cyclase was also abolished. These data suggest functional deterioration of G-proteins, especially Gi, in diabetic retina. Further studies using retinal rod outer segments revealed deterioration in light-sensitive, guanosine triphosphate-dependent functions of transducin in diabetic rats. Pertussis toxin-catalysed ADP ribosylation of the alpha subunit of transducin, a heterotrimeric G-protein of rod outer segments, was also reduced in diabetes. No functional effects were seen in purified subunits of transducin subjected to non-enzymatic glycation in vitro. On the other hand, incubation of non-diabetic rod outer segments with (12-0-tetradeconyl) phorbol-13-acetate, a protein kinase C agonist, in the presence of magnesium and adenosine triphosphate resulted in the reduction of guanosine triphosphate-binding and hydrolysis, thus indicating that protein kinase C may be involved in the regulation of these activities. The significance of these observations in the early visual abnormalities associated with diabetes is discussed.

    Topics: Adenosine Diphosphate Ribose; Adenylate Cyclase Toxin; Animals; Cyclic GMP; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetic Retinopathy; Glucose; Glycosylation; GTP Phosphohydrolases; GTP-Binding Proteins; Guanosine 5'-O-(3-Thiotriphosphate); Guanosine Triphosphate; Kinetics; Pertussis Toxin; Rats; Rats, Inbred Strains; Retina; Rod Cell Outer Segment; Transducin; Virulence Factors, Bordetella

1992