title: Modulation of arterial baroreflex control of muscle sympathetic nerve activity by muscle metaboreflex in humans.
abstract: We aimed to investigate the interaction [with respect to the regulation of muscle sympathetic nerve activity (MSNA) and blood pressure] between the arterial baroreflex and muscle metaboreflex in humans. In 10 healthy subjects who performed a 1-min sustained handgrip exercise at 50% maximal voluntary contraction followed by forearm occlusion, arterial baroreflex control of MSNA (burst incidence and strength and total activity) was evaluated by analyzing the relationship between beat-by-beat spontaneous variations in diastolic arterial blood pressure (DAP) and MSNA both during supine rest (control) and during postexercise muscle ischemia (PEMI). During PEMI (vs. control), 1) the linear relationship between burst incidence and DAP was shifted rightward with no alteration in sensitivity, 2) the linear relationship between burst strength and DAP was shifted rightward and upward with no change in sensitivity, and 3) the linear relationship between total activity and DAP was shifted to a higher blood pressure and its sensitivity was increased. The modification of the control of total activity that occurs in PEMI could be a consequence of alterations in the baroreflex control of both MSNA burst incidence and burst strength. These results suggest that the arterial baroreflex and muscle metaboreflex interact to control both the occurrence and strength of MSNA bursts.
authors.affiliation: Institute of Health and Sport Sciences, University of Tsukuba, Tsukuba City, Ibaraki 305-8574, Japan.
authors.forename: Masashi
authors.initials: M
authors.lastname: Ichinose
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Saito
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Wada
authors.forename: Asami
authors.initials: A
authors.lastname: Kitano
authors.forename: Narihiko
authors.initials: N
authors.lastname: Kondo
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishiyasu
mesh_terms: D000328:Adult; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D003971:Diastole / Q000502:physiology; D015444:Exercise / Q000502:physiology; D005260:Female; D005542:Forearm / Q000098:blood supply; D018737:Hand Strength; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D008297:Male; D018482:Muscle, Skeletal / Q000098:blood supply / Q000294:innervation*; D012016:Reference Values; D012044:Regression Analysis; D013564:Sympathetic Nervous System / Q000502:physiology*