| Autor: |
Klassen SA; Department of Kinesiology, Brock University, St Catharines, ON, Canada., Limberg JK; Department of Nutrition and Exercise Physiology, University of Missouri, Columbia, MO, United States., Harvey RE; Anesthesiology, Mayo Clinic, Rochester, Minnesota, United States., Wiggins CC; Department of Kinesiology, Michigan State University, East Lansing, MI, United States., Spafford JE; Brock University, Canada., Iannarelli NJ; Health Sciences, Brock University, St. Catharines, Ontario, Canada., Senefeld JW; Department of Health and Kinesiology, University of Illinois Urbana-Champaign, Urbana, Illinois, United States., Nicholson WT; Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States., Curry TB; Departments of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States., Joyner MJ; Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States., Shoemaker JK; Kinesiology, Western University, London, Ontario, Canada., Baker SE; Department of Anesthesiology and Perioperative Medicine, Mayo Clinic, Rochester, MN, United States. |
| Abstrakt: |
What is the purpose of sympathetic neuronal action potential (AP) discharge and recruitment patterns for human vascular regulation? This study tested the hypothesis that sympathetic neuronal discharge and recruitment patterns regulate neuropeptide Y (NPY) bioavailability. We used microneurography to record muscle sympathetic nerve activity (MSNA) and a continuous wavelet transform to detect sympathetic APs during a baseline condition and intravenous dexmedetomidine infusion (α 2 -adrenergic agonist, 10 min loading infusion of 0.225 µg kg -1 ; maintenance infusion of 0.1-0.5 µg kg h -1 ) in six healthy individuals (5 females, 27 ± 6 years). Arterial blood samples provided NPY (enzyme-linked immunosorbent assay) and norepinephrine (Liquid Chromatography Tandem Mass Spectrometry) levels during baseline and the dexmedetomidine maintenance infusion. Linear mixed model regressions assessed the relationships between AP discharge, recruitment, and neurotransmitter levels. Across baseline and the dexmedetomidine condition, NPY levels were positively related to mean arterial pressure (β = 1.63 [0.34], P = 0.002), total AP clusters (β = 0.90 [0.22], P = 0.005), and AP frequency (β = 0.11 [0.03], P = 0.003). Norepinephrine levels were not related to mean arterial pressure (β = 0.03 [0.02], P = 0.133) but were positively related to total AP clusters (β = 19.50 [7.07], P = 0.030) and AP frequency (β = 2.66 [0.81], P = 0.014). These data suggest that sympathetic neuronal discharge and recruitment patterns regulate NPY and norepinephrine bioavailability in healthy adults. As such, sympathetic neuronal firing strategies are important for human vascular regulation. |
