title: Consideration on step duration to assess open-loop static characteristics of the carotid sinus baroreflex in rats.
abstract: The carotid sinus baroreflex is one of the most important negative feedback systems to stabilize arterial pressure. Although static characteristics of the carotid sinus baroreflex can be assessed by using a stepwise input protocol under baroreflex open-loop conditions, the step duration has been determined empirically. In the present study, we examined the effects of different time windows (5-10, 15-20, 25-30, 35-40, 45-50, and 55-60 s) on the static characteristics estimated by using a 60-s stepwise input protocol in 10 anesthetized rats. Based on the results, we compared the static characteristics between actual 60-s and 20-s stepwise input protocols. Most of the parameters of the static characteristics did not differ significantly between the 60-s and 20-s stepwise input protocols, suggesting that the open-loop baroreflex static characteristics can be estimated by using a stepwise input with the step duration as short as 20 s in normal rats.
authors.affiliation: Department of Cardiovascular Dynamics, National Cerebral and Cardiovascular Center, 565-8565 Osaka, Japan. torukawa@res.ncvc.go.jp
authors.forename: Toru
authors.initials: T
authors.lastname: Kawada
authors.forename: Shuji
authors.initials: S
authors.lastname: Shimizu
authors.forename: Yusuke
authors.initials: Y
authors.lastname: Sata
authors.forename: Atsunori
authors.initials: A
authors.lastname: Kamiya
authors.forename: Kenji
authors.initials: K
authors.lastname: Sunagawa
authors.forename: Masaru
authors.initials: M
authors.lastname: Sugimachi
mesh_terms: D000818:Animals; D017704:Baroreflex / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology*; D002346:Carotid Sinus / Q000502:physiology*; D003198:Computer Simulation; D025461:Feedback, Physiological / Q000502:physiology; D006339:Heart Rate / Q000502:physiology*; D008297:Male; D008955:Models, Cardiovascular; D051381:Rats; D017207:Rats, Sprague-Dawley