An agonist of 5-HT1B and 5-HT1D receptors (Kis = 2.51 and 3.98 nM, respectively); selective for 5-HT1B and 5-HT1D over 5-HT1A, 5-HT1E, 5-HT1F, 5-HT2A, 5-HT2C, 5-HT3, and 5-HT7 receptors, as well as dopamine D1, D2, and D3, histamine H1, and α1-adrenergic receptors (Kis = >50 nM); induces contractions in human basilar arteries isolated post-mortem, coronary arteries from transplant recipient hearts, and coronary arteries from donor hearts unsuitable for transplantation (EC50s = 13.8, 41.69, and 15.49 nM, respectively); increases carotid vascular resistance in closed-chest and open-chest anesthetized dogs (ED50s = 6 and 1 nmol/kg, i.v., respectively)