Does Intravenous Glucose Infusion Affect Catecholamines in Hypothalamic Ventromedial Nucleus?

Aim: We aimed to investigate the effects of intravenous glucose infusion in dopamine and its metabolite
dihydroxyphenylacetic acid, norepinephrine and its metabolite dihydroxyphenylglycol levels in ventromedial
nucleus (VMN) by brain microdialysis method.
Patients and Methods: 2 groups of normally fed (saline and glucose administered) and 2 groups of 24 hours
food restricted (saline and glucose administered) male adult Wistar albino rats were used. Microdialysis
samples were collected at 20-minute intervals. After recording the first samples, 1.4 ml/kg 50% glucose
solution and 0.9% saline were infused via tail vein. Then, other microdialysis samples were collected for 40
minutes from satiated and fasted rats. All microdialysis samples were analyzed by HPLC-ECD system. All
values were normalised with controls before application and sta tistically analysed by SPSS 20.0.
Results: While dopamine concentrations didn’t change in physiological saline administered fasted and
satiated animals and glucose-administered fasted animals, a statistically insignificant increase was noticed
in glucose-administered satiated groups. DOPAC concentrations showed a statistically significant increase in
satiated glucose group compared to control group about DOPAC concentrations (p=0.004).
Conclusion: Dopaminergic neurotransmission in VMN may vary with blood glucose level. Hyperglycemia
following food intake may contribute to the feeling of satiety by increasing dopaminergic neurotransmitter
concentration in VMN.