microinjection of monoamines , noradrenaline , phenylephrine and 5-hydroxytryptamine ( 5-ht ) into nucleus dorsalis raphe elicited hypertension and tachycardia which could be blocked by local pretreatment with piperoxan ( an alpha-adrenoceptor blocker ) and methysergide ( a 5-ht receptor blocker ) respectively .
C0020538
hypertension
C0025842
methysergide