What question did this study set out to answer?

To determine the relaxant effects of nifedipine on contractions induced by potassium, histamine, and 5-hydroxytryptamine in isolated human pulmonary arteries and veins.

March 1, 1983Journal of Cardiovascular Pharmacology

Effects of Nifedipine on Contractile Responses to Potassium, Histamine, and 5-Hydroxytryptamine in Isolated Human Pulmonary Vessels

View Full Paper

Ask AI

Bookmark

Population

Isolated human pulmonary arteries and veins cut to ring preparations

Comparison

Nifedipine (0.003-3 microM) vs No nifedipine

Design

Preclinical

Authors

EMErich O. MikkelsenAarhus University ASAbdul Moneim Rashad SakrAarhus Municipality LJLennard Tang JespersenAarhus University Hospital

Discussion

Member takes

Implication

Nifedipine may relax pulmonary vessels via calcium entry blockade; leaves open translation to human pulmonary hypertension therapy.

Key Points

To determine the relaxant effects of nifedipine on contractions induced by potassium, histamine, and 5-hydroxytryptamine in isolated human pulmonary arteries and veins.
Tested ring preparations of isolated human pulmonary arteries and veins contracted with potassium (127 mM), histamine (90 microM), and 5-hydroxytryptamine (47 microM).
Administered nifedipine in increasing concentrations (0.003–3 microM) and assessed the role of extracellular calcium using calcium-free and calcium-supplemented (0 to 4 mM) solutions.
Nifedipine induced concentration-dependent relaxation across all agonists, demonstrating greater relaxant efficacy against potassium-induced contractions than those induced by histamine or 5-hydroxytryptamine.
Arteries and veins displayed similar relaxation magnitudes, though high concentrations of nifedipine produced significantly greater relaxation against potassium-induced contractions in veins than in arteries.
Contractile responses to potassium were nearly abolished in calcium-free media; re-adding calcium restored contraction without nifedipine, but nifedipine almost completely abolished this calcium-mediated restoration.

Structured PICO

Population

Isolated human pulmonary arteries and veins cut to ring preparations

Intervention

Nifedipine (0.003-3 microM)

Comparator

No nifedipine (baseline contractions induced by potassium, histamine, or 5-hydroxytryptamine)

Outcome

Relaxant effect on contractions induced by potassium, histamine, or 5-hydroxytryptaminesurrogate

Nifedipine relaxes human pulmonary vessels by inhibiting extracellular calcium entry, with greater efficacy against depolarization-induced contractions than receptor-mediated ones.

Cite This Study

Mikkelsen et al. (1983) studied this question.

synapsesocial.com/papers/6a72bbf084cc45bb7be028f6 https://doi.org/10.1097/00005344-198303000-00025

View Full Paper

Ask AI

Bookmark

Effects of Nifedipine on Contractile Responses to Potassium, Histamine, and 5-Hydroxytryptamine in Isolated Human Pulmonary Vessels

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Effects of Nifedipine on Contractile Responses to Potassium, Histamine, and 5-Hydroxytryptamine in Isolated Human Pulmonary Vessels

Discussion

Member takes

Implication

Key Points

Structured PICO

Cite This Study

Also Consider

Also Consider