The dopamine antagonist flupentixol does not alter ghrelin-induced food intake in rats.
It has been shown that dopamine antagonists suppress the ghrelin-induced increased motivation to work for food. The aim of this study was to investigate the influence of the dopamine antagonist flupentixol on ghrelin-induced food intake. Ad libitum fed male Sprague-Dawley (SD) rats were injected intraperitoneally (ip) with vehicle plus vehicle, vehicle plus ghrelin (13 μg/kg), 0.25mg/kg or 0.5mg/kg flupentixol plus ghrelin, or 0.25mg/kg or 0.5 mg/kg flupentixol plus vehicle. In a second experiment, intracerebroventricularly (icv) cannulated rats received an ip injection of vehicle (0.15M NaCl) or flupentixol (0.25mg/kg) and 20 min later an icv injection of vehicle or ghrelin (1 μg/rat). Both experiments were performed twice: first, rats were offered only standard chow, while in the second experiment they could choose between standard chow and a palatable/preferred chow. Cumulative light phase food intake was assessed for 7h. Ip as well as icv injected ghrelin reliably increased intake of standard chow. Flupentixol did not affect ghrelin-induced intake of standard chow. Ip injected ghrelin failed to increase the intake of palatable chow, whereas icv injected ghrelin did. This effect was not blocked by ip flupentixol. In summary, ip administered ghrelin did not increase the intake of chow the rats preferred; whereas icv injected ghrelin further stimulated the intake of preferred chow suggesting a direct central mediation of this effect. Our results show that the dopamine antagonist flupentixol does not influence ghrelin-induced feeding in our choice paradigm.
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Kim-Marie
KM
Engster
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Jamina
J
Wismar
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Arthur L
AL
Kroczek
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Pauline
P
Teuffel
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Sandra
S
Nolte
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Matthias
M
Rose
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany.
Andreas
A
Stengel
Charité Center for Internal Medicine and Dermatology, Division of General Internal and Psychosomatic Medicine, Charité-Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany. Electronic address: peter.kobelt@charite.de.
Peter
P
Kobelt
D000818:Animals; D018492:Dopamine Antagonists / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004435:Eating / Q000187:drug effects*; D005475:Flupenthixol / Q000008:administration & dosage / Q000494:pharmacology*; D005518:Food Preferences; D054439:Ghrelin / Q000037:antagonists & inhibitors*; D007274:Injections, Intraperitoneal; D007276:Injections, Intraventricular; D008297:Male; D010507:Periodicity; D051381:Rats; D017207:Rats, Sprague-Dawley
D018492:Dopamine Antagonists; D054439:Ghrelin; D005475:Flupenthixol
Brain; Dopamine; Flupentixol; Food intake; Ghrelin; Rat