Effect of L-5-Hydroxytryptophan on drinking behavior in Coturnix japonica (Temminck and Schlegel, 1849) (Galliformes: Aves): involvement of renin-angiotensin system.
The purpose of this study was to explore the role of L-5-hydroxytryptophan (L-HTP) and its relationship with the renin-angiotensin system (RAS) on the drinking behavior in Japanese quails. Normally-hydrated quails that received injections of L-HTP (12.5; 25 and 50 mg.kg-1) by the intracoelomic route (ic) expressed an increase in water intake, which was inhibited by captopril, an angiotensin converting enzyme (ACE) inhibitor. In addition, captopril also induced such a response in birds under previous fluid deprivation. High doses of captopril (35-70 mg.kg-1, sc) in normally-hydrated quails decreased the spontaneous water intake while low doses of captopril (2-5 mg.kg-1, sc) did not prompt water intake after L-HTP administration. Losartan, an AT1 receptor antagonist in mammals, did not change the water intake levels in normally-hydrated or water-deprivated birds. Serotonin (5-HT) injections did not provoke its known dipsogenic response.
Cedraz-Mercez
P L
PL
Departamento de Ciências Fisiológicas, Instituto de Biologia, Universidade Federal Rural do Rio de Janeiro, Seropédica, RJ, 23890-000, Brazil.
Almeida
A C
AC
Thomaz
C M
CM
Costa-e-Sousa
R H
RH
Olivares
E L
EL
Côrtes
W S
WS
Medeiros
M A
MA
Reis
L C
LC
D006916:5-Hydroxytryptophan / Q000494:pharmacology*; D000806:Angiotensin-Converting Enzyme Inhibitors / Q000494:pharmacology; D000818:Animals; D002216:Captopril / Q000494:pharmacology; D003370:Coturnix / Q000502:physiology*; D004327:Drinking Behavior / Q000187:drug effects* / Q000502:physiology; D008297:Male; D012084:Renin-Angiotensin System / Q000187:drug effects* / Q000502:physiology; D013997:Time Factors
D000806:Angiotensin-Converting Enzyme Inhibitors; D002216:Captopril; D006916:5-Hydroxytryptophan