Effect of third ventricle administration of L-694,247, a selective 5-HT1D receptor agonist, on water intake in rats.
L-694,247, a selective 5-HT1D receptor agonist, injected directly into the third ventricle (2.5, 5.0, and 10.0 micrograms/rat) of dehydrated rats induced a dose-dependent partial blockade of water intake. Injected in this way, the compound abolishes drinking behavior induced by third ventricle administration of carbachol (2 micrograms/rat), angiotensin II (5 ng/rat), and isoproterenol (40 micrograms/rat). In addition, intraventricular injections of L-694,247 did not modify water intake in normohydrated rats. The effects of L-694,247 are due to a specific interaction with 5-HT1D receptors, because its inhibitory effect on water intake in dehydrated rats is blocked by the previous administration of a 5-HT1D antagonist, GR 127935 (5 micrograms/rat), directly into the third ventricle. It is concluded that central 5-HT1D receptor activation disrupts the functional integrity of central pathways related to drinking behavior.
De Castro-e-Silva
E
E
Department of Physiology, Federal University of Bahia, Salvador, Brazil.
Sarmento
C
C
Nascimento
T A
TA
Luz
C P
CP
Soares
T
T
Marinho
A
A
Cunha
M
M
Bulcäo
C
C
De Oliveira
I R
IR
Fregoneze
J B
JB
D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000804:Angiotensin II / Q000494:pharmacology; D000818:Animals; D002217:Carbachol / Q000494:pharmacology; D004326:Drinking / Q000187:drug effects*; D007276:Injections, Intraventricular; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D008845:Microinjections; D018721:Muscarinic Agonists / Q000494:pharmacology; D010069:Oxadiazoles / Q000008:administration & dosage / Q000494:pharmacology*; D010879:Piperazines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D044346:Receptor, Serotonin, 5-HT1D; D011985:Receptors, Serotonin / Q000187:drug effects*; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000008:administration & dosage / Q000494:pharmacology*; D014363:Tryptamines / Q000008:administration & dosage / Q000494:pharmacology*; D014868:Water Deprivation
D000318:Adrenergic beta-Agonists; D018721:Muscarinic Agonists; D010069:Oxadiazoles; D010879:Piperazines; D044346:Receptor, Serotonin, 5-HT1D; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D014363:Tryptamines; D000804:Angiotensin II; C085632:L 694247; C090701:GR 127935; D002217:Carbachol; D007545:Isoproterenol