title: Effect of angiotensin II on some behavioral and neurochemical measures of the central serotonine system.
abstract: The effects of angiotensin II (AII) given intracerebroventricularly (icv.) on behaviors controlled by central serotonine (5-HT) and on some neurochemical measures of central 5-HT function have been investigated in rats. AII (0.1 and 0.5 micrograms) increased the 5-HT (20 micrograms, icv.) and L-tryptophan (200 mg/kg, ip.) induced hyposensitivity to painful electric stimuli delivered to the animals feet. Also AII (0.5 micrograms) intensified yawning, a 5-HT dependent behavior. This effect was decreased or abolished, respectively, by mianserin (3 mg/kg, i.p.) or cyproheptadine (1 mg/kg, i.p.), the 5-HT receptors blockers. AII, however, influenced neither the slight hyposensitivity of rats to electric current caused by 5-hydroxytryptophane (5-HTP, 12.5 and 25 mg/kg, ip.) nor the number of 'Wet-Dog' shakes evoked by 5-HTP (100 mg/kg, i.p.). Also, the peptide did change the rate of 5-HTP accumulation in brain measured after pretreatment of the animals with L-tryptophan (200 and 500 mg/kg, i.p.) preceded by the inhibition of central aromatic amino acid decarboxylase. In vitro AII (10(-5) - 10(-9) mol/l) did not affect release and only slightly increased uptake of 3H-5-HT by blood platelets. The data indicate that AII stimulates central 5-HT neurotransmission and that this action does not result from the peptide interference with the synthesis, release and uptake of 5-HT.
mesh_terms: D006916:5-Hydroxytryptophan / Q000378:metabolism; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects*; D001923:Brain Chemistry / Q000187:drug effects*; D003533:Cyproheptadine / Q000494:pharmacology; D004597:Electroshock; D005277:Fenfluramine / Q000494:pharmacology; D006900:Hydroxylation; D007276:Injections, Intraventricular; D007700:Kinetics; D008297:Male; D008803:Mianserin / Q000494:pharmacology; D010830:Physostigmine / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D012701:Serotonin / Q000502:physiology*; D014364:Tryptophan / Q000378:metabolism
chemical_list: D000804:Angiotensin II; D008803:Mianserin; D005277:Fenfluramine; D003533:Cyproheptadine; D012701:Serotonin; D014364:Tryptophan; D010830:Physostigmine; D006916:5-Hydroxytryptophan