Shigeki Nishimoto

Increased fructose-lysine of hair protein in diabetic patients

SummaryFructose-lysine, which is formed by binding glucose to lysine, is degraded on acid hydrolysis into furosine. Furosine was determined by high-performance liquid chromatography according to the method of Schleicher et al. Furosine values were significantly higher in diabetic patients than in healthy subjects, and significantly correlated with haemoglobin A1 (HbA1) values. These results suggest that furosine, like HbA1, may become an indicator of long-term blood glucose control in diabetic patients and be useful in investigating diabetic complications on the level of tissue.

Evaluation of periflux blood flow measurement in diabetic patients with autonomic neuropathy

The periflux blood flow (PBF) response pattern in the fingertips determined with a periflux laser Doppler flowmeter was analyzed in a standing test in which the subject was instructed to stand up from the sitting position and in Valsalvas maneuver in which respiration was held for 10 s at the maximum inspiration, and indicators such as reaction time (RT), orthostatic dysreaction rate (ODR) and PBF decreasing velocity (PDV) were established for determining autonomic abnormality. RT and ODR were significantly correlated with the change in blood pressure and pulse rate, respectively, in the standing test, and PDV was significantly correlated with beat-to-beat variation. Abnormalities were found in about half of the diabetics in the standing test and Valsalvas maneuver. These results suggested that the analysis of PBF changes in the standing and Valsalvas tests may be an easy and useful approach for clinical examination of the autonomic nervous system.

Age- and diabetes-accelerated glycation in the human aorta.

The extent of glycation in pieces of human aorta was estimated by determining the content of furosine, which is derived from fructose-lysine through acid hydrolysis. Glycation of human aorta was found to increase with advancing age. A significant positive correlation was found between the degree of atherosclerosis and the furosine level in the aorta in subjects over 60 years of age. Furthermore, the furosine level in the aortae of diabetic patients was significantly higher than that in normal subjects of the same age. These results suggest not only that glycation in the aorta may increase with aging and with the development of arteriosclerosis, but also that diabetes may be related as well to premature aging as to arteriosclerosis.

A specific method of glycosylated hemoglobin using furosine measurement

In order to get an accurately specific determination of glycosylated hemoglobin (GHb-f), the furosine assay method, which can detect epsilon-amino-lysine-bound glucose, was investigated. A good correlation was found between GHb-f values obtained by this method and HbA1 values by conventional ion exchange column chromatography. It was, therefore, considered that this technique would be a new useful method for determining glycosylated hemoglobin.