Deguine V, Menasche M, Ferrari P, Fraisse L, Pouliquen Y, Robert L
INSERM U86, Institut des Cordeliers, Paris, France.
Int J Biol Macromol. 1998 Feb;22(1):17-22. doi: 10.1016/s0141-8130(97)00084-6.
The degradation of hyaluronan was followed by viscosimetry and by HPLC in order to study the possible role of Maillard products (lysine-glucose) on the alteration of the vitreous gel in aging and diabetes. Lysine-glucose generated Maillard products produced a decrease of viscosity and of the number average molecular weight (Mn) of hyaluronan during a 1 h incubation at 37 degrees C. This effect was comparable to that produced by 1 U/ml of testicular hyaluronidase but was weaker than the effect of a Fenton-type reagent (Udenfriend's reagent). The polydispersity of hyaluronan incubated with Maillard products appeared higher than with hyaluronidase suggesting a more random reaction. Antioxydant enzymes (SOD, catalase), the iron chelators (desferrioxamine, transferrin) and the free radical scavengers (uric acid, carnosine) inhibited the degradation by Maillard products confirming its free radical nature and the intervention of trace metals. Maillard products have been detected in diabetic vitreous and may play a role in its accelerated modifications (liquefaction) in diabetes as compared to normal aging.
为了研究美拉德产物（赖氨酸 - 葡萄糖）在衰老和糖尿病过程中对玻璃体凝胶改变可能发挥的作用，采用粘度测定法和高效液相色谱法跟踪透明质酸的降解情况。在37℃孵育1小时期间，赖氨酸 - 葡萄糖生成的美拉德产物导致透明质酸的粘度和数均分子量（Mn）降低。这种作用与1 U/ml睾丸透明质酸酶产生的作用相当，但比芬顿型试剂（尤登弗试剂）的作用弱。与透明质酸酶孵育相比，与美拉德产物孵育的透明质酸的多分散性似乎更高，这表明反应更随机。抗氧化酶（超氧化物歧化酶、过氧化氢酶）、铁螯合剂（去铁胺、转铁蛋白）和自由基清除剂（尿酸、肌肽）抑制了美拉德产物的降解，证实了其自由基性质以及痕量金属的干预。在糖尿病患者的玻璃体中已检测到美拉德产物，与正常衰老相比，其可能在糖尿病中玻璃体加速改变（液化）过程中发挥作用。
