“However, the responses to the dose of ergotamine were strikingly reduced when the cats were previously treated with the adrenaline antagonists phenoxybenzamine (5 mg/kg) or ergotamine (50 mug/kg).”
“The stimulant actions of adrenaline, ergotamine and ergometrine were also protected against the blocking action of phenoxybenzamine by treating the muscle with a high concentration of ergometrine instead of adrenaline.”