Reduced glucose-induced neuronal activation in the hypothalamus of diet-induced obese rats.
Rats predisposed to develop diet-induced obesity (DIO) preferentially activate their sympathetic nervous system during intracarotid glucose infusion [B.E. Levin, Intracarotid glucose-induced norepinephrine response and the development of diet-induced obesity, Int. J. Obesity 16 (1992) 451-457.] but their brains are generally less responsive to glucose than diet-resistant rats (DR) [B.E. Levin, K.L. Brown, A.A. Dunn-Meynell, Differential effects of diet and obesity on high and low affinity sulfonylurea binding sites in the rat brain, Brain Res. 739 (1996) 293-300.; B.E. Levin, B. Planas, Defective glucoregulation of brain alpha2-adrenoceptors in obesity-prone rats, Am. J. Physiol. 264 (1993) R305-R311.; B.E. Levin, A.C. Sullivan, Glucose-induced norepinephrine levels and obesity resistance, Am. J. Physiol. 253 (1987) R475-R481.; B.E. Levin, A.C. Sullivan, Glucose-induced sympathetic activation in obesity-prone and resistant rats, Int. J. Obesity 13 (1989) 235-246.]. Here, 1 h intracarotid glucose infusions (4 mg/kg/min) selectively increased Fos-like immunoreactivity (FLIR) in the hypothalamic paraventricular, ventromedial, dorsomedial and arcuate nuclei of inbred DR but not DIO rats. This suggests that enhanced glucose-induced sympathetic activation in DIO rats is related to a failure of glucose to produce neuronal activation in these areas.
Levin
B E
BE
Neurology Service (127C), VA Medical Center, 385 Tremont Avenue, East Orange, NJ 07018-1095, USA. levin@umdnj.edu
Govek
E K
EK
Dunn-Meynell
A A
AA
D000818:Animals; D001111:Arcuate Nucleus of Hypothalamus / Q000166:cytology / Q000378:metabolism; D004032:Diet; D004302:Dorsomedial Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism; D005947:Glucose / Q000494:pharmacology*; D007031:Hypothalamus / Q000166:cytology / Q000378:metabolism*; D009474:Neurons / Q000737:chemistry / Q000187:drug effects* / Q000502:physiology*; D009765:Obesity / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism; D016760:Proto-Oncogene Proteins c-fos / Q000032:analysis; D051381:Rats; D011922:Rats, Mutant Strains; D017207:Rats, Sprague-Dawley; D013493:Suprachiasmatic Nucleus / Q000166:cytology / Q000378:metabolism; D013495:Supraoptic Nucleus / Q000166:cytology / Q000378:metabolism; D014697:Ventromedial Hypothalamic Nucleus / Q000166:cytology / Q000378:metabolism
D016760:Proto-Oncogene Proteins c-fos; D005947:Glucose