Effects of fluoxetine administration on regional galanin expression in obese Zucker rat hypothalamus.
The aim of the present work was to study the potential involvement of hypothalamic galanin system in the anorectic mechanism of fluoxetine in obese Zucker rats. Male obese Zucker (fa/fa) rats were administered fluoxetine (10 mg/kg; i.p.) daily for two weeks. The control group was given 0.9% NaCl solution. Significant decreases in food intake, final body weight and total body fat were observed after fluoxetine treatment. Although fluoxetine-treated rats showed a decrease in urine elimination, this effect was not enough to compensate decreased water intake, leading to dehydration, as showed by decreased body water content. Chronic fluoxetine administration increased the numbers of galanin positively immunostained neural cells in medial and lateral preoptic areas, lateral hypothalamic area and paraventricular nucleus (rostral and magnocellular regions), without changes in dorsomedial, ventromedial, supraoptic, suprachiasmatic and arcuate nuclei. Taken into account that galanin stimulates appetite, these results could represent rather a compensatory response against reduced food intake than a direct anorectic mechanism. Changes in the magnocellular region of the hypothalamic paraventricular nucleus suggest a role for galanin neural circuits at this level in fluoxetine-induced hydro-osmotic impairment.
Churruca
Itziar
I
Department of Nutrition and Food Science, University of the Basque Country, Paseo de la Universidad 7, 01006 Vitoria, Spain.
Portillo
María P
MP
Gutiérreza
Arantza
A
Casis
Luis
L
Macarulla
María Teresa
MT
Zarate
Jon
J
Echevarría
Enrique
E
D000273:Adipose Tissue; D000818:Animals; D001823:Body Composition; D001835:Body Weight / Q000187:drug effects; D004435:Eating / Q000187:drug effects; D005473:Fluoxetine / Q000008:administration & dosage*; D019004:Galanin / Q000032:analysis*; D007031:Hypothalamus / Q000737:chemistry* / Q000187:drug effects*; D008297:Male; D009765:Obesity / Q000378:metabolism*; D010286:Paraventricular Hypothalamic Nucleus / Q000737:chemistry / Q000187:drug effects; D011301:Preoptic Area / Q000737:chemistry / Q000187:drug effects; D051381:Rats; D011924:Rats, Zucker; D017367:Selective Serotonin Reuptake Inhibitors / Q000008:administration & dosage*
D005473:Fluoxetine; D019004:Galanin; D017367:Selective Serotonin Reuptake Inhibitors