Abstract
Although it has been reported that habitual exercise increase cardiovagal baroreflex sensitivity, the precise mechanism responsible for its modulation remains unknown. Some previous studies indicate a relation between arterial compliance and cardiovagal baroreflex sensitivity. Also, it has been reported that habitual exercise increase arterial compliance, so that the baroreflex sensitivity increse. However, it is unclear vascular stiffness fully explain the modulation of the baroreflex sensitivity. We hypothesized that habitual exercise may also modulate the neural component of the arterial baroreflex. The aim of this study is to examine mechanical and neural component of the arterial baroreflex between sedentary and exercise trained men. Mchanical component of the arterial baroreflex was estimated by the mechanical transduction of pressure into barosensory stretch (Δcarotid vessel diameter/ΔAP). Neural component of the arterial baroreflex was estimated by the neural transduction of stretch into vagal outflow (ΔR-R interval/Δcarotid vessel diameter). Integrated cardiovagal baroreflex sensitivity was assessed by carotid and radial AP and HR. [Jpn J Physiol 55 Suppl:S105 (2005)]
