AGEs are especially bad when they form in-vivo. That is, lysine-arginine dimers (pentosidine), Ne-carboxymethyllysine, argpyrimidine, etc. These serve
to crosslink, amoung other things, collagen. This results in lowered tissue elasticity and, amoung other things, amyloidosis, hardened arteries and
cataracts.
A study (if I can find it) found an equivalent amount of collagen crosslinking in a 27 year old uncontrolled diabetic and a 70 year hold.
In these cases, the blood sugar is forming AGEs with the free (usually N-e-NH2 lysine and Arginine) amino groups of nearby proteins. Maillard
reaction (browning of food) happens at low temperatures, it just takes a long time, a high sugar titre, or both.
The analytical methods would involve the quantification of thing like pentosidine dimers. There is, IIRC a polyclonal antibody with a fluorescent tag
which has been developed.
Cheers,
O3
OK, see the Who's Who of Maillard reaction, in-vivo, which should get you started!
Extracted from a presentation I gave on this in grad. school (carbohydrate chemistry is my thing):
* Friedman, E.A. (1999). Advanced Glycosylated End Products and Hyperglycemia in the Pathogenesis of Diabetic Complications. Diabetes Care. 22 (suppl.
2.) B65-B71.
* Sasaki, N., Fukatsu, R., Tsuzuki, K., Hayashi, Y., Yoshida, T., Fujii, N. Koike, T., Wakayama, I., Amano, N. and Makita, Z. (1998). Advanced
Glycation End Products in Alzheimer’s Disease and Other Neurodegenerative Diseases. J. Am. Pathol. 153 (4), pp. 1149-1155.
* Ranjan, M., Nayak, S. and Rao, B.S. (2006). Immunochemical detection of glycated b- and g- crystallins in lens and their circulating autoantibodies
(IhG) in streptozocin induced diabetic rat. Molecular Vision 12, pp. 1077-1085.
* Grandee, S.K. and Monnier, V.M. (1991). Mechanism of Formation of the Maillard Protein Cross-Link Pentosidine. J. Biol. Chem. 266 (18), pp. 11649-
* Sato, T., Shigamoto, N., Wu, X., Kikuchi, S., Yamagishi, S-i. and Takeuchi, M. (2006). Toxic Advanced Glycation End Products (TAGE) Theory in
Alzheimer’s Disease. Am. J. Alzheimer’s Disease & Other Dementias. 21 (3), pp. 197-207.
* Kessel, L., Kalinin, S., Nagaraj, R.H., Larsen, M., Johansson, L.B.A. (2002). Time-resolved Steady-State Fluorescence Spectroscopic Studies of the
Human Lens with comparison to Argpyrimidine, Pentosidine and 3-OH-kynurenine. Photochem. Photobiol. 76 (5), pp. 549-554.
* Monnier, V.M. and Cerami, A. (1981). Nonenzymatic Browning in vivo: Possible Process for Aging of Long-Lived proteins. Science, 211, pp. 491-493.
* Dyer, D.G., Dunn, J.A., Thorpe, S.R., Bailie, K.E., Lyons, T.J., McCance, D.R. and Baynes, J.W. (1993). Accumulation of Maillard Reaction Products
in Skin Collagen in Diabetes and Aging. Am. Soc. Clin. Invest. 91, pp. 2463-2469.
* Farboud, B., A-K, A., Miyata, T., Hjelmeland, L.M. and Handa, J.T. (1999). Development of a Polyclonal Antibody with Broad Epitope Specificity for
Advanced Glycation Endproducts and Localization of these Epitopes in Bruch’s Membrane of the Aging Eye. Mol. Vis. 5:11. Http://www.
Molvis.org/molvis/v5/p11>
[Edited on 2-10-2009 by Ozone] |