Autonomic Blockade for High Blood Pressure

Recruiting in Palo Alto (17 mi)

Overseen byItalo Biaggioni, MD

Age: 18+

Sex: Any

Travel: May Be Covered

Time Reimbursement: Varies

Trial Phase: Phase 1

Waitlist Available

Sponsor: Vanderbilt University

No Placebo Group

Trial Summary

What is the purpose of this trial?

The purpose of this study is to better understand the role of the abdominal veins (splanchnic capacitance) and the sympathetic nervous system in human hypertension. The investigators will test the hypothesis that constriction of abdominal veins due to sympathetic activation contributes to human hypertension. Splanchnic capacitance will be assessed in normotensive and hypertensive subjects at baseline and during acute blockade of the autonomic nervous system.

Research Team

Italo Biaggioni, MD

Principal Investigator

Vanderbilt University

Eligibility Criteria

This trial is for men and women aged 18-65 with high blood pressure, not on medication affecting autonomic functions, and without chronic diseases like diabetes or cardiovascular issues. Participants should be non-smokers, not pregnant, have a BMI under 40 kg/m2, and no strong family history of hypertension in lean normotensive subjects.

Inclusion Criteria

I am between 18 and 65 years old.

Subjects able and willing to provide informed consent

I have normal blood pressure or controlled high blood pressure.

Exclusion Criteria

My BMI is over 40.

I do not have a strong family history of high blood pressure, sleep apnea, and I am not a highly trained athlete.

I am a current smoker or have a history of heavy smoking.

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Treatment Details

Interventions

Nitroglycerin (Vasodilator)
Trimethaphan (Autonomic Nervous System Blocker)

Trial OverviewThe study aims to understand the role of abdominal veins (splanchnic capacitance) and sympathetic nervous system activity in hypertension by using Trimethaphan and Nitroglycerin to block autonomic nervous system signals temporarily.

Participant Groups

2Treatment groups

Experimental Treatment

Group I: Study day with trimethaphanExperimental Treatment1 Intervention

After baseline measurements, autonomic blockade will be induced by continuous intravenous infusion of trimethaphan starting at 0.5-1.0 mg/min and increasing by 1.0 mg/min every 2 to 6 minutes up to an infusion rate of 5 mg/min.

Group II: Radionuclide Study day with nitroglycerinExperimental Treatment1 Intervention

Sublingual nitroglycerin (0.3-0.6 mg) will be given after baseline measurements. Outcome measurements will be repeated within 10 min after the nitroglycerin has dissolved