Influence of 5-HT1A agonist on the feeding behavior of Coturnix japonica (Galliformes: Aves).
In this study, we investigate the effect of serotonin receptor 5-HT1A stimulation on the feeding behavior of quails (Coturnix japonica). The administration of 5-HT1A agonist, 8-OH-DPAT (0.05 to 5.0 mg/Kg) dose-dependently inhibited the food intake in normally fed quails. Greater inhibition was attained with 5.0 mg/kg (0.93 +/- 0.21 g vs. 5.83 +/- 0.25 g, P < 0.05, 2 h after food offer). A comparable response was obtained from previously fasted quails. At end of 2 h, a higher dose of 8-OH-DPAT induced more intense hypophagy (1.59 +/- 0.41 g vs. 6.85 +/- 1.04 g, P < 0.0001). Previous treatment with the antagonist 5-HT1A/beta-adrenergic, propranolol, failed to block the inhibitory action of 8-OH-DPAT, but instead, intensified it (controls, 5.22 +/- 1.09 g; 8-OH-DPAT, 1.41 +/- 0.19 g; propranolol + 8-OH-DPAT, 0.44 +/- 0.25 g, P < 0.01, for all comparisons). The administration of an isolated higher dose of propranolol induced a hypophagic action (controls, 4.5 +/- 0.8 g vs. propranolol, 2.0 +/- 0.2 g, P < 0.01). Current outcomes suggest a possible role of 5-HT1A receptor on the feeding behavior of quails, as opposed to mammals. On the other hand, the intensified hypophagy induced by previous administration of propranolol raises the hypothesis of a beta-adrenergic excitatory mechanism that controls the feeding behavior of quails.
Reis
L C
LC
Departamento de Ciências Fisiológicas, Instituto de Biologia, UFRuralRJ, CEP 23890-000, Seropédica, RJ, Brazil. lcreis@ufrrj.br
Marinho
V R
VR
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology*; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D000818:Animals; D003370:Coturnix / Q000502:physiology*; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology; D008297:Male; D011433:Propranolol / Q000494:pharmacology; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects* / Q000502:physiology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*; D013997:Time Factors
D000319:Adrenergic beta-Antagonists; D017366:Serotonin Receptor Agonists; D044282:Receptor, Serotonin, 5-HT1A; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D011433:Propranolol