Levels of hypothalamic neurotransmitters in lean and obese Zucker rats.
Hypothalamic neurotransmitter levels were compared between groups of Zucker rats. Animals were grouped by gender, phenotype and preference for dietary fat. Before sacrifice all animals consumed a standard rat chow diet and were fasted overnight. Five rats from each of eight groups were assayed. Hypothalamic regions (lateral, LH; ventromedial, VMH; paraventricular, PVN) and the raphe were isolated and analyzed for dopamine, norepinephrine, epinephrine, serotonin and 5-hydroxyindoleacetic acid. A factorial analysis of variance was used to compare the concentrations of these biogenic amines in the four regions across phenotypic, gender and fat preference profiles. No differences were demonstrated between groups based upon fat food preference. Epinephrine and 5-HIAA content varied between lean and obese animals but there were no differences in the content of serotonin, norepinephrine or dopamine. The results are consistent with the hypothesis that the obese animal eats more because it releases less of the satiety-inducing neurotransmitter serotonin in the hypothalamus.
Svec
Frank
F
Obesity Research Program Department of Medicine, Louisiana State University Health Sciences Center, New Orleans 70112, USA. fsvec@lsuhsc.edu
Thompson
Hilary
H
Corll
Connie
C
Porter
Johnny
J
D000704:Analysis of Variance; D000818:Animals; D004041:Dietary Fats; D004298:Dopamine / Q000378:metabolism; D004837:Epinephrine / Q000378:metabolism; D005260:Female; D005518:Food Preferences; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D018377:Neurotransmitter Agents / Q000378:metabolism*; D009765:Obesity / Q000503:physiopathology*; D009928:Organ Specificity; D051381:Rats; D011924:Rats, Zucker; D012701:Serotonin / Q000378:metabolism; D012727:Sex Characteristics; D013851:Thinness / Q000503:physiopathology*
D004041:Dietary Fats; D018377:Neurotransmitter Agents; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D004298:Dopamine; D004837:Epinephrine