DPP (Dipeptidyl Peptidase)-4 Inhibition Potentiates the Vasoconstrictor Response to NPY (Neuropeptide Y) in Humans During Renin-Angiotensin-Aldosterone System Inhibition

What Was Tested

The paper reports a study of Neuropeptide Y, published as a randomized controlled trial.

NPY (neuropeptide Y) is coreleased with norepinephrine, causes vasoconstriction via the Y1 receptor, and is degraded by DPP4 to NPY (3-36) in vitro.

The researchers tested the hypothesis that DPP4 inhibition would potentiate the vasoconstrictor effect of NPY.

Who Took Part

The study group was 5 subjects.

By PubMed's age tags, the people studied were young adults, adults and middle-aged adults, both men and women.

On the last day of treatment, NPY was infused by brachial artery and forearm blood flow was measured using plethysmography.

How the Study Was Run

The researchers set it up as a randomized, double-blind, placebo-controlled and crossover study.

Because people in this Neuropeptide Y study were split into groups at random, differences between the groups are less likely to reflect who happened to join each one.

Neither the subjects nor the staff measuring them knew who was on Neuropeptide Y, so expectations could not easily colour the readings.

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

Each person switched between Neuropeptide Y and the comparison at some point, usually with a gap in between.

What Was Measured

The researchers tested the hypothesis that DPP4 inhibition would potentiate the vasoconstrictor effect of NPY.

The subject headings attached to it are Antihypertensive Agents, Blood Pressure, Diabetes Mellitus, Type 2, Drug Synergism, Neuropeptide Y, Renin-Angiotensin System and Sitagliptin Phosphate.

Author keywords: heart failure, hypertension, norepinephrine, renin-angiotensin-aldosterone system and vasoconstriction.

What This Means in Plain Language

The paper is a randomized, double-blind and placebo-controlled study of Neuropeptide Y in 5 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.

The publication is from 2018 (Hypertension (Dallas, Tex. : 1979)), a journal based in United States.

More context: the Neuropeptide Y compound page, all human trials.