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

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Abstract
Human postmortem digital arteries obtained 6-60 h after death were used for in vitro studies of vascular smooth mucle physiology and pharmacology. Isometric tension was recorded from spiral strips in tissue baths at 37.degree. 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; histamine and potassium chloride were weaker agonists. The order of sensitivities to the agonists tested was angiotensin > 5-hydroxytryptamine > norepinephrine > histamine > barium chloride > potassium chloride. Both competitive (phentolamine) and noncompetitive (phenoxybenzamine) antagonism of norepinephrine was demonstrated. Phentolamine was also a weak inhibitor of 5-hydroxytryptamine. Cyproheptadine was a potent antagonist of 5-hydroxytryptamine, but had less effect against norepinephrine. This suggests the presence of separate receptors for 5-hydroxytryptamine and norepinephrine in these vessels. The response to barium chloride was inhibited by the Ca-antagonist, verapamil. The .alpha.-adrenoceptor antagonist, phentolamine, was not effective against barium chloride. 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 peripheral vascular site.