Endothelial Hyperpolarization in Humans

What Was Tested

In this phase 2 trial, researchers set out to test Bradykinin for hyperparathyroidism.

A second purpose of the study is to determine the identity of EDHF.

It had two arms (groups): Healthy Controls (experimental) and Risk Factors (experimental).

Healthy subjects had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine.

Non-hypertensive subjects with cardiovascular risk factors had venous occlusion plethysmography after intra-arterial infusions of saline, L-NG-monomethyl Arginine (L-NMMA), Tetraethylammonium (TEA), fluconazole, bradykinin, sodium nitroprusside and acetylcholine.

The registry classes the interventions as drug.

More on the Plan

The vascular endothelium synthesizes at least four potent vasodilator substances: nitric oxide (NO), prostacyclin, carbon monoxide and endothelium-derived hyperpolarizing factor (EDHF) that contribute to vasodilator tone, and to inhibition of platelet activation and inflammation.

EDHF release is stimulated by receptor-dependent agonists such as acetylcholine and bradykinin (BK), and leads to hyperpolarization of the underlying smooth muscle cells presumably by opening Ca2+-activated K+ channels.

Who Took Part

Enrollment: 174 actual participants took part.

It was open to people of any sex aged from 21 years up to 65 years.

Healthy volunteers could join, not only people with the condition.

Examples of who could join: Hyperlipidemic (LDL \> 140).

The full record lists 2 inclusion and 8 exclusion criteria; among the exclusions: diabetes mellitus; cardiovascular disease; use of any regular medications.

How the Study Was Run

The set-up was non-randomized, single-group and open-label.

Being open-label, the Bradykinin study did not mask who received what.

Everyone received the same intervention, so there was no separate comparison group inside the trial.

It started in 2002-07 with completion listed for 2013-01.

It ran at 1 site in United States.

Its stated primary purpose is diagnostic.

What Was Measured

It also tracked 9 secondary outcomes, for example Change in Tissue Plasminogen Activator (t-PA) Release, Change in Tissue Plasminogen Activator (t-PA) Release After Tetraethylammonium (TEA) and Bradykinin Administration, Change in Tissue Plasminogen Activator (t-PA) Release After Fluconazole and Bradykinin Administration and Change in Tissue Plasminogen Activator (t-PA) Release After Fluconazole, Tetraethylammonium (TEA), and Bradykinin Administration.

What This Means in Plain Language

Put simply, this is a phase 2, non-randomized trial of Bradykinin in 174 people with hyperparathyroidism.

It ended early (terminated); results are posted on the registry, and this page does not restate them.

More context: the Bradykinin compound page, Hyperparathyroidism research.