Decrease of Glucose Utilization Rate in the Spinal Cord of Experimental 2,5-Hexanedione Poisoning Rats. Application of Microdetermination Technique.

Abstract

To examine the effects of 2,5-hexanedione (HD) on the glucose metabolism in the spinal cord, glucose utilization rate (GUR) and distribution volume of glucose (DV) were measured in the white matter and anterior horn of the spinal cord in 8 rats exposed to HD for 4 weeks and in 10 control rats. The GUR and DV were determined by the quantitative microdetermination method using non-tracer 2-deoxyglucose based on the three-compartments model of Sokoloff. GURs in the white matter and anterior horn and DV in the anterior horn in the HD-exposed rats were significantly lower than those in the control rats. In the multiple regression analysis, GUR in the white matter of HD-exposed rats was significantly related to blood HD concentration. It is suggested that the decrease of GUR in the white matter is a major effect of HD in the spinal cord.

Alteration of Glucose Metabolism in the Spinal Cord of Experimental Lead Poisoning Rats. Microdetermination of Glucose Utilization Rate and Distribution Volume.

“…This suggests that the axons and Schwann cells are not main targets of lead toxicity. On the other hand, the GUR in the white matter of the spinal cord was decreased and related to blood 2,5-hexanedione (HD) concentrations in 2,5-HD exposed rats 14) , in accordance with the findings that the white matter is affected greatly by 2,5-HD 15) . Thus, it is probable that the measurement of GUR and DV reflects the biochemical changes underlying neurotoxicity; application of the method presented here could provide information for understanding the mechanisms of toxicity.…”

“…The decrease in conversion of [ ] glucose into lactate, citrate and malate was observed in cerebral cortex slices obtained from two groups of rats with mean blood lead (BPb) concentrations of 31.8 and 54.2 µg/dl, respectively, which had been given drinking water containing 200 or 600 ppm of lead for 20 days 1) . The conversion rate of [ 14 C] glucose to 14 CO 2 was reduced in brain capillaries isolated from cerebral cortex of calves with BPb of 118 ± 0.19 µg/dl, which were given 15 mg/kg bw of lead acetate orally for 7 to 8 days, showing no histopathological changes 2) . Uptake of glucose analog (3-O-methylglucose) by the MEly cells (a cell line of mouse cerebral microvessel endothelium) was inhibited after the cells were incubated with a medium containing 10 -4 M of lead for 2 days 3) .…”