A human arterial preparation for studying the effects of vasoactive agents.

Human postmortem digital arteries obtained between 6 and 60 hours after death were used for in vitro studies of vascular smooth muscle physiology and pharmacology.Isometric tension was recorded from spiral strips in tissue baths at 37°C.The responses were durable and reproducible and were similar to those of 10 operative specimens of visceral arteries.The contractile force of the preparations was unrelated to the time elapsed since death.Norepinephrine, 5-hydroxytryptamine, and barium chloride gave the strongest responses; histamlne and potassium chloride were weaker agonists.Hie order of sensitivities to the agonists tested was angiotensin > 5hydroxytryptamine > norepinephrine > histamlne > barium chloride > potassium chloride.Both competitive (phentolamlne) and noncompetitive (phenoxybenzamlne) antagonism of DorepiDephrine was demonstrated.Pbentolamine was also a weak inhibitor of 5-hydroxytryptamine.Cyprobeptadine was a potent antagonist of 5-hydroxytryptamine, but had less effect against norepinephrine.This suggests the presence of separate receptors for 5hydroxytryptamine and norepinephrine in these vessels.The response to barium chloride was inhibited by the calcium-antagonist, verapamil.The o-adrenoceptor antagonist, phentolamlne, was not effective against barium chloride.We conclude that human postmortem digital arteries can be studied effectively in vitro.The preparation should be useful for the evaluation of drugs that are thought to act at a peripberal vascular site.