Glucokinase Is a Critical Regulator of Ventromedial Hypothalamic Neuronal Glucosensing

• DOI: 10.2337/diabetes.55.02.06.db05-1229
• Publication Date: 2006-06-01T23:03:17Z
• Authors: Ling Kang; Ambrose A. Dunn-M...; Vanessa H. Routh; Larry D. Gaspers; Yasufumi Nagata; Teruyuki Nishimura; Junichi Eiki; Bei B. Zhang; Barry E. Levin
• Keywords: Glucokinase

To test the hypothesis that glucokinase is a critical regulator of neuronal glucosensing, activity was increased, using activator drug, or decreased, RNA interference combined with calcium imaging in freshly dissociated ventromedial hypothalamic nucleus (VMN) neurons primary hypothalamus (VMH; VMN plus arcuate nucleus) cultures. assess validity our approach, we first showed glucose-induced (0.5–2.5 mmol/l) changes intracellular Ca2+ concentration ([Ca2+]i) oscillations, fura-2 and membrane potential (using potential–sensitive dye), were highly correlated both glucose-excited -inhibited neurons. Also, increased (half-maximal effective [EC50] = 0.54 glucose-inhibited decreased inhibitory [IC50] 1.12 [Ca2+]i oscillations to incremental glucose from 0.3 5 mmol/l. In untreated VMH cultures, expression mRNA number demonstrable glucosensing fell spontaneously by half over 12–96 h without loss viable Transfection small interfering did not affect survival but reduce 90% association all 99% reduction A pharmacological produced dose-related increase (EC50 0.98 decrease (IC50 0.025 μmol/l) held at 0.5 mmol/l glucose. Together, these data support role for glucosensing.