CCR5 antagonists (Tali Digital Ltd)

SYNOPSISThe effects of several drugs usually considered as serotonin (5HT) ‐antagonists were studied in a model of the external carotid circulation, the canine nasal vascular bed. 1. It was confirmed that 5‐HT constricts this vascular bed but that after administration of a large dose of ergotamine (10–2 mg/kg i.v.), 5‐HT dilates the nasal vessels. 2. All drugs studied (Org GB 94, Org GC 94, ergotamine, dihydroergotamine, methysergide, pizotifen, cyproheptadine and clonidine) at relatively low concentrations can potentiate 5‐HT induced vasoconstriction. 3. At higher doses of these drugs the 5‐HT response is inhibited.4. The vasodilator response to 5‐HT obtained in erotamine‐treated dogs is inhibited by all other agents investigated.