title: The interaction of central nitrergic and GABAergic systems on food intake in neonatal layer-type chicks.
abstract: Most physiological behaviors such as food intake are controlled by the hypothalamus and its nuclei. It has been demonstrated that injection of the paraventricular nucleus of the hypothalamus with nitric oxide (NO) donors elicited changes in the concentration of some amino acids, including GABA. Also, central nitrergic and GABAergic systems are known to provide inputs to the paraventricular nucleus and are involved in food intake control. Therefore, the present study examines the probable interaction of central nitrergic and GABAergic systems on food intake in neonatal layer-type chicks. The results of this study showed that intracerebroventricular (ICV) injection of L-arginine (400 and 800 nmol), as a NO donor, significantly decreased food intake (P < 0.001), but ICV injection of Nω-Nitro-L-arginine methyl ester (L-NAME) (200 and 400 nmol), a NO synthesis inhibitor, increased food intake (P < 0.001). In addition, the orexigenic effect of gaboxadol (0.2 µg), a GABAA agonist, was significantly attenuated in ICV co-injection of L-arginine (200 nmol) and gaboxadol (0.2 µg) (P < 0.001), but it was significantly amplified in ICV co-injection of L-NAME (100 nmol) and gaboxadol (0.2 µg) (P < 0.001). On the other hand, the orexigenic effect of baclofen (0.2 µg), a GABAB agonist, did not change in ICV co-injection of L-arginine (200 nmol) or L-NAME (100 nmol) with baclofen (0.2 µg) (P > 0.05). Also, the hypophagic effect of L-arginine (800 nmol) was significantly amplified in ICV co-injection of picrotoxin (0.5 µg), a GABAA antagonist, or CGP54626 (21 ng), a GABAB antagonist, with L-arginine (800 nmol) (P < 0.001). These results probably suggest an interaction of central nitrergic and GABAergic systems on food intake in neonatal layer-type chicks and GABAA receptors play a major role in this interaction.
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, 14155-6453, Iran.
authors.forename: Kasra
authors.initials: K
authors.lastname: Mokhtarpouriani
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, 14155-6453, Iran. zendedel@ut.ac.ir.
authors.forename: Morteza
authors.initials: M
authors.lastname: Zendehdel
authors.affiliation: Department of Basic Sciences, Faculty of Veterinary Medicine, Shahid Bahonar University of Kerman, Kerman, Iran.
authors.forename: Hossein
authors.initials: H
authors.lastname: Jonaidi
authors.affiliation: Department of Physiology, Faculty of Veterinary Medicine, University of Tehran, Tehran, 14155-6453, Iran.
authors.forename: Vahab
authors.initials: V
authors.lastname: Babapour
authors.affiliation: Department of Parasitology, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran.
authors.forename: Parviz
authors.initials: P
authors.lastname: Shayan
mesh_terms: D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000378:metabolism; D002645:Chickens / Q000502:physiology*; D004435:Eating; D005247:Feeding Behavior; D005260:Female; D007031:Hypothalamus / Q000378:metabolism*; D008297:Male; D009569:Nitric Oxide / Q000378:metabolism*; D011963:Receptors, GABA-A / Q000378:metabolism; D005680:gamma-Aminobutyric Acid / Q000378:metabolism*
chemical_list: D011963:Receptors, GABA-A; C026512:arginine methyl ester; D009569:Nitric Oxide; D005680:gamma-Aminobutyric Acid; D001120:Arginine
keywords: Food intake; GABA; NO; Neonatal layer-type chick