Effects of the 5-HT1 receptor agonists DP-5-CT, CGS 12066B, and RU 24969 on plasma adrenaline and glucose levels in the rat.
Recent results have indicated that the 5-HT1A receptor subtype mediates the adrenaline-releasing and hyperglycemic effects of 8-hydroxy-2-(di-n-propylamino)tetralin in the rat. The aim of this study was to analyse, by means of the peripherally acting 5-HT1A receptor agonist, N,N-dipropyl-5-carboxamidotryptamine (DP-5-CT), whether these 5-HT1A receptors are peripherally or centrally localised. In view of the appreciable affinity of DP-5-CT for the 5-HT1D receptor subtype, the effects of the mixed 5-HT1B/5-HT1D receptor agonist 7-trifluoromethyl-4-(4-methyl-1-piperazinyl)-pyrrolo(1,2-a)quinoxaline (CGS 12066B), and the mixed 5-HT1A/5-HT1B/5-HT1D receptor agonist 5-methoxy-3(1,2,3,6-tetrahydropyridine-4-yl)1H-indole (RU 24969) were also investigated. Administration of DP-5-CT (0.3 and 1 mg/kg i.v.) increased plasma glucose levels dose-dependently, whereas only the 1 mg/kg dose of DP-5-CT elicited a rise in plasma adrenaline levels. In contrast, CGS 12066B (1.5 and 4.5 mg/kg i.v.) did not affect either plasma adrenaline or plasma glucose levels. Administration of RU 24969 (0.5-4.5 mg/kg i.v.) increased dose-dependently both plasma adrenaline and glucose levels. The data suggest that central 5-HT1A receptors, but neither 5-HT1B nor 5-HT1D receptors, regulate plasma adrenaline and glucose levels.
Laude
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Laboratoire de Pharmacologie, CNRS, CHU Necker-EM, Paris, France.
Baudrie
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Martin
G R
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Chaouloff
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F
D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004837:Epinephrine / Q000097:blood*; D007211:Indoles / Q000494:pharmacology*; D008297:Male; D011810:Quinoxalines / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D011985:Receptors, Serotonin / Q000187:drug effects / Q000502:physiology*; D014363:Tryptamines / Q000494:pharmacology*
D001786:Blood Glucose; D007211:Indoles; D011810:Quinoxalines; D011985:Receptors, Serotonin; D014363:Tryptamines; C052561:CGS 12066B; C025145:5-methoxy 3-(1,2,3,6-tetrahydro-4-pyridinyl)1H indole; C055895:N,N-dipropylcarboxamidotryptamine; D004837:Epinephrine