The Abnormally High Level of Uric D-Ribose for Type-2 Diabetics

Abstract

In 1815,the French chemist Michel Eugene Chevreul(1786-1889) discovered that the sweetness in the urine of diabetics comes from grape sugar or D-glucose.Diabetes mellitus(DM) is considered as a group of metabolic diseases characterized by hyperglycemia(high concentration of blood D-glucose) resulting from defects in insulin secretion,insulin action,or both.On the other hand,D-ribose as an energetic enhancer was found to decrease the concentration of blood D-glucose,and thus "Oral administration of D-ribose in diabetes mellitus" was ever described by Steinberg and colleagues(1970).As described previously in this laboratory,D-ribose rapidly glycates proteins,such as BSA,neuronal Tau and α-synuclein,producing advanced glycation end products(AGEs) with severe cyt o toxicity,leading to dysfunction and cell death,in vitro and in vivo.Intraperitoneal injection of D-ribose into mice significantly increases their glycated serum protein and blood AGEs though the concentration of D-glucose became slightly decreased,suggesting that D-ribose is much easier to produce AGEs than D-glucose in vivo.Here,using 4-(3-Methyl-5-oxo-2-pyrazolin-1-yl) benzoic acid(MOPBA) coupled with HPLC,we determined the concentration of uric D-ribose of type 2 diabetic patients(n=30) and the age-matched healthy controls(n=30).The results show that the yield of the derivative of MOPBA-ribose is linearly correlated with the concentration of D-ribose(r2=0.999) with a recovery of 99%.The isolated fractions of D-ribose and D-glucose from urine of type 2 diabetic patients through HPLC were analyzed by mass spectrometry,and the results showed that the fractions contained 569.19 u compound(C27 H29 N4 O10,D-ribose),and 599.20 u compound(C28 H31 N4 O11,D-glucose) respectively.The concentration of uric D-ribose of Type 2 diabetics(male(134.28±35.09) μmol/L,female(97.33± 23.68) μmol/L) was significantly(P 0.001) higher than that of the age-matched healthy control(male(35.99 ± 5.64) μmol/L,female(33.72 ±6.27) μmol/L).Under the experimental conditions,the uric D-glucose level of the patients was also markedly(P 0.001) higher than the control.Further analyses showed a marked increase in the level of uric D-ribose from either male(P 0.001) or female(P 0.001),but a significant difference of the uric levels between male and female could not be observed(P 0.05).The high levels of uric D-ribose and D-glucose of the patients suggest that type 2 diabetic patients are not only suffered from D-glucose metabolism disorders,but also from D-ribose metabolism disorders.