"CP-93129"

superior mesenteric artery and mesenteric resistance arteries in which the contractile 5- HT2A receptor was antagonized. Maximum concentrations of BW-723C86 (5- HT2B agonist), CP 93129 (5-HT1B agonist) or LP-44 (5-HT7 agonist) did not relax the superior mesenteric artery from DOCA-salt rats vs. vehicle. Additionally, 5-HT (10-9 M to 10-5 M) did not cause relaxation in either contracted mesenteric

(WAY 100635 [0.2-0.8 mg/kg subcutaneous] and SB 216641 [0.2-0.8 mg/kg subcutaneous]) or agonists (8-OH-DPAT [0.25-1 mg/kg subcutaneous] and CP 93129 [0.125-0.5 mg/kg subcutaneous]) of 5-HT1A and 5-HT1B receptors, respectively, were determined in the hot-plate test in mice. Acetaminophen (300-800 mg/kg) showed a dose-dependent antinociceptive effect in the hot-plate test in mice. WAY 100635 (0.2-0.8 mg/kg; 5-HT1A antagonist) induced an increase in the antinociceptive effect of 600 mg/kg acetaminophen, but this increase was not dose related. Conversely, 8-OH-DPAT (0.25-1 mg/kg; 5-HT1A agonist) decreased the antinociceptive effect of acetaminophen. SB 216641 (0.2-0.8 mg/kg; 5-HT1B antagonist) induced a dose-related increase in the antinociceptive effect of acetaminophen, and CP 93129 (0.25 mg/kg

, NBQX (22.8 +/- 16 % of control, P < 0.001). In contrast, the 5-HT2 antagonist, ritanserin, had no effect on the amplitude of these EPSCs (106 +/- 31 % of control, P = n.s.). 5-HT reduced these EPSCs to 50.0 +/- 13 % of control (P < 0.001), as did the 5-HT1A agonist, 8-OH-DPAT (52.5 +/- 17 %, P < 0.001) and the 5-HT1B agonist, CP 93129 (40.6 +/- 29 %, P < 0.01). 8-OH-DPAT and CP 93129 increased

under pharmacological block of GABA(A), GABA(B), and 5-HT(1A) receptors. 3 The 5-HT(1B) receptor selective agonist 1,4-dihydro-3-(1,2,3,6-tetrahydro-4-pyridinyl)-5H-pyrrolo[3,2-b]pyridin-5-one dihydrochloride (CP 93129) inhibited poly-epscs (EC(50)=55 nM), an effect mimicked by the 5-HT(1B) ligands 5-carboxamidotryptamine (5-CT; EC(50)=14 nM) and methylergometrine (EC(50)=78 nM), but not by 1-(3 -chlorophenyl)piperazine dihydrochloride (mCPP; 10 micro M) or 7-trifluoromethyl-4(4-methyl-1-piperazinyl)-pyrrolo[1,2-a]quinoxaline dimaleate (CGS 12066B; 10 micro M). 4 The effects of CP 93129 and 5-CT were blocked by the selective 5-HT(1B) receptor antagonist 3-[3-(dimethylamino)propyl]-4-hydroxy-N-[4-(4-pyridinyl)phenyl]benzamide dihydrochloride (GR 55562; K(B) approximately 100 nM) and by cyanopindolol

into the ventromedial nucleus of the hypothalamus with 0, 50, 100 or 200ng of the 5-HT(1B) receptor agonist, 1,4-dihydro-3-(1,2,3,6-tetrahydro-4-pyridinyl)-5H-pyrrol[3,2-bi]pyridin-5-one-dihydrochloride (CP 93129). Sexual receptivity was monitored by the lordosis to mount (L/M) ratio. EO rats showed a transient decline in lordosis behavior following infusion with the saline vehicle and this was amplified by CP 93129