The purpose of this study is to see what the differences are in sweat (amount and small molecule content) collected from different sites of the body and by different methods of sweat stimulation. Additionally, the investigators want to know whether the amount and small molecule content of the sweat is the same in an individual over time, and the same across individuals at a given time. Finally, the investigators want to know how consumption of over-the-counter anti-inflammatory drugs such as ibuprofen will affect the inflammatory mediator content of sweat and how that compares to blood. This information will help to better understand the composition and behavior of sweat and assess its potential utility as a routine clinical tool in skin research.
Subjects will participate in 4 study day visits that will be scheduled about 1- week apart. During the first study visit, the investigators will compare sweat collected following pharmacological stimulation of sweating (using the drug pilocarpine) to sweat collected following physiological stimulation of sweating (using a stationary bicycle). During the second study visit, the investigators will collect sweat following stimulation of sweating by the drug pilocarpine from the inner part of the forearm (near the wrist) and also the upper surface of the thigh (near the knee). During the third study visit, the investigators will collect sweat following stimulation of sweating by the drug pilocarpine from the inner part of both forearms (near the wrist). During the fourth study visit, the investigators will collect a sweat sample following stimulation of sweating by the drug pilocarpine from the inner part of the forearm (near the wrist) and a blood sample (about one teaspoon) from the other arm. After blood and sweat collection, participants will consume 400 mg (two tablets) of ibuprofen. The investigators will then collect blood and sweat from 30 minutes, 2 hours and 4 hours after participants consume the ibuprofen.
Study Type
INTERVENTIONAL
Allocation
NA
Purpose
BASIC_SCIENCE
Masking
NONE
Enrollment
14
400 mg ibuprofen given to inhibit cyclooxygenase metabolism
15 minutes exercise at 60-80% oxygen consumption to induce sweating
Iontophoresis with a 1.5 milliampere (mA) current using a gel disc containing a 5% pilocarpine nitrate solution to induce sweating
Western Human Nutrition Research Center
Davis, California, United States
Volar Forearm Sweat Lipid Mediator Concentrations Following Pilocarpine Stimulation
Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.
Time frame: measured at study visit 1, 2 and 3; detected lipid mediator concentrations for study visit 1 reported
Volar Forearm Sweat Lipid Mediator Concentrations Following Exercise
Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.
Time frame: measured at study visit 1, detected lipid mediator concentrations reported
Lower Back Sweat Lipid Mediator Concentrations Following Pilocarpine Stimulation
Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.
Time frame: measured at study visit 1, detected lipid mediator concentrations reported
Anterior Distal Thigh Sweat Lipid Mediator Concentrations Following Pilocarpine Stimulation
Approximately 150 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids and endocannabinoid-like molecules, and sphingolipids.
Time frame: measured at study visit 2, detected lipid mediator concentrations reported
Change in Plasma Lipid Mediator Concentrations Before and After Oral Ibuprofen Administration
Approximately 100 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids, and endocannabinoid-like molecules.
Time frame: measured at four timepoints at study visit 4, detected lipid mediator concentrations for first timepoint reported
Change in Pilocarpine-stimulated Sweat Lipid Mediator Concentrations Before and After Oral Ibuprofen Administration
Approximately 100 lipid mediators will be measured by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Assayed lipid mediators include oxygenated lipids, endocannabinoids, and endocannabinoid-like molecules.
Time frame: measured at four timepoints at study visit 4, detected lipid mediator concentrations for first timepoint reported
Change in Plasma Ibuprofen Concentrations
Plasma concentration of ibuprofen prior to and 30 min, 2 hr and 4 hr after oral administration
Time frame: measured at four timepoints at study visit 4
Change in Sweat Ibuprofen Concentrations
Sweat concentration of ibuprofen prior to and 30 min, 2 hr and 4 hr after oral administration
Time frame: measured at four timepoints at study visit 4
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