Species variation in the cerebrovascular response to neurotransmitters and related vasoactive agents

Constrictory and dilatory responses of pial arteries to various receptor stimulants and modulators were evaluated in vitro and compared in rat, rabbit, cat and man. For the constrictory response, differences were noted especially in the rabbit, which responded strongly to histamine but poorly to noradrenaline and prostaglandin F2 alpha. Histamine was a prominent dilator, but only in rat and man. Isoprenaline induced effective vasodilation only in rat, and dopamine was efficient only in human pial arteries.