Effects of losartan on cerebral and ocular circulation in healthy subjects.

What Was Tested

This randomized controlled trial looks at Angiotensin II and Losartan.

The introduction of specific inhibitors of AT1 receptors, such as losartan, has enabled the investigation of the renin-angiotensin-system (RAS) in humans in vivo.

Haemodynamic effects of orally administered losartan were investigated with non-invasive methods.

Who Took Part

The study group was 10 subjects.

PubMed indexes the participants as adults, men only.

Pulsatile choroidal blood flow was estimated with laser interferometric measurement of fundus pulsation.

How the Study Was Run

The design is described as randomized, double-blind, placebo-controlled and crossover.

The subjects were allocated by chance, so the Angiotensin II group and the comparison group should start out alike.

Blinding on both sides kept the subjects and researchers unaware of who received Angiotensin II.

A placebo (an inactive look-alike) gave the Angiotensin II group a baseline to be compared against.

In the crossover set-up each of the subjects took both Angiotensin II and the comparison in turn, acting as their own control.

In addition, the effect of losartan on haemodynamic changes induced by exogenous angiotensin II (Ang II) was assessed.

Blood flow velocities in the ophthalmic and the middle cerebral artery (OA, MCA) were measured with Doppler sonography.

What Was Measured

PubMed files the paper under topics including Angiotensin II, Angiotensin Receptor Antagonists, Antihypertensive Agents, Blood Flow Velocity, Brain, Echoencephalography and Eye.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Angiotensin II and Losartan in 10 subjects.

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 4 sentences of the abstract; we leave them to the paper itself rather than summarise them.

The publication is from 1997 (British journal of clinical pharmacology), a journal based in England.

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