title: Regular endurance exercise in young men increases arterial baroreflex sensitivity through neural alteration of baroreflex arc.
abstract: Endurance exercise training increases arterial baroreflex sensitivity that corresponds to alteration in vessel wall compliance of the carotid artery in elderly men. Here, we examined whether regular endurance exercise increases arterial baroreflex sensitivity through neural alteration of the baroreflex arc in young men. We assessed arterial baroreflex sensitivity in eight sedentary men (age 24 +/- 1 yr) and nine men trained in endurance exercise (age 23 +/- 1 yr) during phase IV of the Valsalva maneuver [systolic arterial blood pressure (SAP)-R-R interval relationship]. Arterial baroreflex sensitivity was further analyzed by dividing the mechanical component [SAP-end-systolic carotid lumen diameter relationship (ultrasonography)] and the neural component (end-systolic carotid lumen diameter-R-R interval relationship). Carotid arterial compliance was determined using B-mode ultrasound and arterial applanation tonometry on the common carotid artery. Arterial baroreflex sensitivity and its neural component were greater in the exercise-trained group (P < 0.05). In contrast, carotid arterial compliance and the mechanical component of arterial baroreflex sensitivity did not differ between groups. These results suggest that regular endurance exercise in young men increases arterial baroreflex sensitivity through changes in the neural component of the baroreflex arc and not through alterations in vessel wall compliance of the carotid artery.
authors.affiliation: Institute for Human Science and Biomedical Engineering, National Institute of Advanced Industrial Science and Technology (AIST Higashi 1-1-1, Tsukuba, Ibaraki 305-8566, Japan. h-komine@aist.go.jp
authors.forename: Hidehiko
authors.initials: H
authors.lastname: Komine
authors.forename: Jun
authors.initials: J
authors.lastname: Sugawara
authors.forename: Koichiro
authors.initials: K
authors.lastname: Hayashi
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Yoshizawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Yokoi
mesh_terms: D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D002302:Cardiac Output; D017536:Carotid Artery, Common / Q000000981:diagnostic imaging / Q000502:physiology*; D003187:Compliance / Q000502:physiology; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D010101:Oxygen Consumption; D010807:Physical Endurance / Q000502:physiology*; D005082:Physical Exertion / Q000502:physiology*; D017534:Radial Artery / Q000502:physiology; D014463:Ultrasonography; D014636:Valsalva Maneuver / Q000502:physiology; D014655:Vascular Resistance / Q000502:physiology; D055815:Young Adult