Effect of high-performance liquid chromatography on plasma angiotensin II measurements in treated and untreated normotensive and hypertensive patients

What Was Tested

Researchers studied Angiotensin II in this controlled clinical trial publication.

To investigate whether the HPLC step was necessary for measuring Ang II in human plasma samples in their laboratory using their own Ang II antiserum.

Why It Was Studied

Angiotensin II (Ang II) levels are normally very low in human plasma, approximately 5 pg/ml.

They are usually measured by radioimmunoassay after extraction and concentration.

Who Took Part

According to the abstract, 29 patients were involved.

In the first study, 108 blood samples were collected from 29 hypertensive patients during placebo or treatment with the Ang II antagonist BMS-186295.

In the second study blood samples were collected from 12 normal subjects before and during beta-adrenergic blockade.

How the Study Was Run

In design terms this was a placebo-controlled study.

Some patients received a placebo instead of Angiotensin II, giving a reference point.

Human plasma Ang II levels, measured with and without the HPLC step, were compared in two different studies.

Since the action of renin is the rate-limiting step in the production of Ang II in plasma, the relationships of plasma renin activity (PRA) to Ang II levels measured with and without HPLC were also evaluated.

What Was Measured

Angiotensin II (Ang II) levels are normally very low in human plasma, approximately 5 pg/ml.

They are usually measured by radioimmunoassay after extraction and concentration.

PubMed files the paper under topics including Adrenergic beta-Antagonists, Angiotensin II, Antihypertensive Agents, Biphenyl Compounds, Blood Chemical Analysis, Blood Pressure and Chromatography, High Pressure Liquid.

What This Means in Plain Language

The paper is a placebo-controlled study of Angiotensin II in 29 patients.

With fewer than 40 people, it is a small study, so it is better read as an early signal for further research than as a settled answer.

Results are reported in around 7 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 1997 (Journal of hypertension), a journal based in Netherlands.

More context: the Angiotensin II compound page, all human trials.