D-Ribose Induces Cellular Protein Glycation and Impairs Mouse Spatial Cognition

BACKGROUND: D-ribose, an important reducing monosaccharide, is highly active in the glycation of proteins, and results in the rapid production of advanced glycation end products (AGEs) in vitro. However, whether D-ribose participates in glycation and leads to production of AGEs in vivo still requires investigation. METHODOLOGY/PRINCIPAL FINDINGS: Here we treated cultured cells and mice with D-ribose and D-glucose to compare ribosylation and glucosylation for production of AGEs. Treatment with D-ribose decreased cell viability and induced more AGE accumulation in cells. C57BL/6J mice intraperitoneally injected with D-ribose for 30 days showed high blood levels of glycated proteins and AGEs. Administration of high doses D-ribose also accelerated AGE formation in the mouse brain and induced impairment of spatial learning and memory ability according to the performance in Morris water maze test. CONCLUSIONS/SIGNIFICANCE: These data demonstrate that D-ribose but not D-glucose reacts rapidly with proteins and produces significant amounts of AGEs in both cultured cells and the mouse brain, leading to accumulation of AGEs which may impair mouse spatial cognition

The effect of treatment of Type 2 (insulin independent) diabetes mellitus on plasma concentrations of pancreatic polypeptide and glucagon

The effect of the control of diabetes with diet and insulin upon plasma levels of human pancreatic polypeptide and glucagon was determined in eight patients with Type 2 (insulin independent) diabetes mellitus. The mean±SEM fasting plasma glucose was 15.9±1.3mmol/l for 5 days of diet treatment and 5.9±0.4 mmol/l for the last 5 days of treatment with diet plus insulin (p < 0.0001); corresponding fasting plasma pancreatic polypeptide levels were 328±97 and 247±71 pg/ml (p < 0.05) and immunoreactive glucagon levels were 95±11 and 62±6 pg/ml (p < 0.005). Cooked ground beef was administered on the first day of diet treatment and on the last day of treatment with diet plus insulin; mean maximal rise of pancreatic polypeptide, and total and incremental plasma pancreatic polypeptide response areas were significantly lower following treatment (p < 0.01), as was total area for immunoreactive glucagon (p < 0.05). Normalisation of fasting plasma glucose by short-term treatment with diet plus insulin is associated with decreases in basal and stimulated secretory activity of the pancreatic polypeptide cells in insulin independent diabetes mellitus.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46016/1/125_2004_Article_BF00251278.pd