Effects of IM Oxytocin on Pupil Diameter and HRV
Study Details
Study Description
Brief Summary
The goal of this study is to test the effects of oxytocin on heart rate variability and pupil diameter, both of which have subtle effects on the activity rate of the autonomic nervous system.
| Condition or Disease | Intervention/Treatment | Phase |
|---|---|---|
|
Phase 4 |
Detailed Description
This protocol focuses on two measures of autonomic control to quantify central actions of oxytocin. First, the study team proposes to examine the influence of oxytocin on heart rate variability with focus on its effect on high frequency variability, most commonly ascribed to parasympathetic nervous system activity acting to brake sympathetic tone. Intranasal oxytocin has been demonstrated to have a large effect size on this measure which can be repeated at frequent intervals. As a secondary assessment of parasympathetic activity, the study team will measure high frequency fluctuation in pupil diameter, termed hippus, which also reflects parasympathetic nervous system activity. This outcome measure can be assessed in 3 seconds using equipment currently being used under Institutional Review Board (IRB) approved protocols.
Study Design
Arms and Interventions
| Arm | Intervention/Treatment |
|---|---|
| Experimental: Oxytocin First, then Placebo Subjects in this arm will receive Intramuscular injection of Oxytocin (Pitocin®), 10 International Units (IU) at the first visit. Then at the next visit, they will receive Intramuscular injection of (1 milliliter) saline. |
Drug: Oxytocin
Oxytocin 10 IU
Other Names:
Drug: Placebo
Placebo
Other Names:
|
| Experimental: Placebo, Then Oxytocin Subjects in this arm will receive intramuscular injection of (1 milliliter) saline at the first visit. Then at the next visit, they will receive Intramuscular injection of Oxytocin (Pitocin®), 10 International Units (IU). |
Drug: Oxytocin
Oxytocin 10 IU
Other Names:
Drug: Placebo
Placebo
Other Names:
|
Outcome Measures
Primary Outcome Measures
- Fluctuation in Pupil Diameter (Hippus) -Pre drug administration [Baseline]
Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter in the .1-2 Hz range, termed hippus. Pupil measurements will be made for 20 seconds every 5 minutes for 20 minutes
- Fluctuation in Pupil Diameter (Hippus) -Post drug administration [up to 90 minutes after study drug administration]
Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter in the .1-2 Hz range, termed hippus. Pupil measurements will be made for 20 seconds every 5 minutes until 90 minutes after study drug administration.
- Fluctuation in Pupil Diameter (Hippus) -Post drug administration [up to 120 minutes after study drug administration]
Magnitude of power at the dominant frequency in the Fourier transform of pupil diameter in the .1-2 Hz range, termed hippus. Pupil measurements will be made for 20 seconds every 5 minutes until 90 minutes after study drug administration.
- Heart rate variability in the high frequency range (HF-HRV) as a reflection of level of parasympathetic nervous system tone [baseline]
Variability in heart rate in the 0.12-0.40 Hz frequency
- Heart rate variability in the high frequency range (HF-HRV) as a reflection of level of parasympathetic nervous system tone [up to 90 minutes after study drug administration]
Variability in heart rate in the 0.12-0.40 Hz frequency
- Heart rate variability in the high frequency range (HF-HRV) as a reflection of level of parasympathetic nervous system tone [up to 120 minutes after study drug administration]
Variability in heart rate in the 0.12-0.40 Hz frequency
Eligibility Criteria
Criteria
Inclusion Criteria:
-
Male or female > 18 and < 66 years of age,
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Body Mass Index (BMI) <40
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Generally in good health as determined by the Principal Investigator based on prior medical history
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Normal blood pressure and resting heart rate without medication
Exclusion Criteria:
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Hypersensitivity, allergy, or significant reaction to any ingredient of Pitocin®
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Any disease, diagnosis, or condition (medical or surgical) that, in the opinion of the Principal Investigator, would place the subject at increased risk
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Women who are pregnant (positive result for serum pregnancy test at screening visit),
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Women who are currently nursing or lactating, women that have been pregnant within 2 years.
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Neuropathy, chronic pain, diabetes mellitus, or taking benzodiazepines or pain medications on a daily basis.
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Previous eye surgery, eye medications, cataracts
Contacts and Locations
Locations
| Site | City | State | Country | Postal Code | |
|---|---|---|---|---|---|
| 1 | Wake Forest Baptist Health | Winston-Salem | North Carolina | United States | 27157 |
Sponsors and Collaborators
- Wake Forest University Health Sciences
Investigators
- Principal Investigator: James C Eisenach, MD, Wake Forest University Health Sciences
Study Documents (Full-Text)
More Information
Publications
- Norman GJ, Cacioppo JT, Morris JS, Malarkey WB, Berntson GG, Devries AC. Oxytocin increases autonomic cardiac control: moderation by loneliness. Biol Psychol. 2011 Mar;86(3):174-80. doi: 10.1016/j.biopsycho.2010.11.006. Epub 2010 Nov 30.
- Turnbull PR, Irani N, Lim N, Phillips JR. Origins of Pupillary Hippus in the Autonomic Nervous System. Invest Ophthalmol Vis Sci. 2017 Jan 1;58(1):197-203. doi: 10.1167/iovs.16-20785.
- IRB00060838