Reflex Responses to Intermittent Hypoxia in Humans: Mechanisms and Consequences

Summary

The overall goal of this project is to better understand the effect of intermittent hypoxia (IH) on sympathetic neuronal discharge patterns in humans, as well as mechanisms that mediate persistent sympathoexcitation with IH.

Conditions

• Sleep Apnea
• Healthy
• Vasoconstriction
• Vasodilation

Interventions

OTHER

Hypoxic exposure

30 minutes of intermittent hypoxia achieved using breaths of low oxygen air (5% oxygen) followed by room air through a mask.

OTHER

modified Oxford test

An intravenous bolus of sodium nitroprusside (100 μg) will be given to decrease blood pressure, followed 1 minute later by a bolus of phenylephrine (150 μg) to increase blood pressure, occurring before and after intermittent hypoxia exposure.

DRUG

Oral Bosentan 62.5 mg

Prior to completion of visit 2, male subjects will consume 62.5 mg twice daily for 3 days as well as the morning of the study visit (7 pills) at home and experimental sessions will be performed 3 hours after oral intake of the final dose.

OTHER

Hypoxic ventilatory response test

Hypoxia will be achieved using breaths of low oxygen air (5% oxygen) followed by room air through a mask. This will be repeated 4-5 times per test, occurring before and after intermittent hypoxia exposure.

Sponsors & Collaborators

• National Heart, Lung, and Blood Institute (NHLBI)

  collaborator NIH

• Mayo Clinic

  collaborator OTHER

• University of Missouri-Columbia

  lead OTHER

Principal Investigators

• Jacqueline K Limberg, Ph.D. · University of Missouri-Columbia

Study Design

Allocation

NA

Purpose

BASIC_SCIENCE

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Max Age

45 Years

Sex

ALL

Healthy Volunteers

Yes

Timeline & Regulatory

Start

2016-12-20

Primary Completion

2018-09-08

Completion

2021-04-12

FDA Drug

Yes

Countries

• United States

Study Locations