Endocrine Abstracts

Objective: It is common in the clinical setting that the reperfusion of glucose after severe hypoglycaemia. Starvation leads to decrease in blood glucose level (BGL) and this shifts the brain to utilize less glucose and utilize other alternative fuels. This led us investigate how the brain decreases the glucose uptake during starvation and how it utilizes the glucose under severe hypoglycaemia.

Results: To understand the mechanism we checked the neuronal glut3, glut1 in expression by western blot analysis in the cortex and hippocampus in 24 h fasted and 2 IU/kg insulin induced hypoglycaemia mice at different intervals (10, 30, and 90 min). Our results suggesting that 24 h fasting significantly decreases the BGL (58±2 mg/dl) from fed mice BGL (120.3±6) and it slightly decreases the glut3 in cortex and hippocampus. In the insulin induced hypoglycaemia group, the BGL of 10 min after was (67.8 mg/dl), 30 min after was (54.80 mg/dl) and 90 min after was below (20 mg/dl). The glut3 expression in the 10 min was not altered but the 30 min after insulin administration decreases the glut3 more but not significant, whereas the glut3 in the 90 min after was restored to normal level. No change in the expression glut1 was observed.

Conclusion: The decreased BGL at the range nearly of 60 mg/dl during fasting or insulin induced hypoglycaemia, the neuron may utilize less glucose (decreased glut3) and may prefer astrocyte lactate (no change in glut1) and other fuel for metabolism. The decreased BGL below 20 mg/dl, the neuron may try to utilize the glucose directly (restored glut3) and from astrocytes (no change in glut1) and also from other fuels to restore the normal metabolism.

Disclosure: This research was supported by Ministry of Education, Culture, Sports, Science and Technology, Japan, and by a grant from the promotion and mutual aid corporation for Private schools, Japan (23602012 and 26460239) respectively.