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- Siegel, G, et al.
(author)
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Vascular smooth muscle, a multiply feedback-coupled system of high versatility, modulation and cell-signaling variability
- 1997
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In: Int J Microcirc. - 0167-6865. ; 17, s. 360-373
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Journal article (peer-reviewed)abstract
- Under normal conditions, the various vascular regulatory effector influences are interwoven in a dynamic, and not a static, circulatory system. The reaction of a smooth muscle cell is thus reflected only incompletely by the stationary activation curve `developed tension versus membrane potential'. The missing time domain in this relationship is a reflection of our as yet limited understanding of the system´s behavior in space and time. It should be emphasized that rythmogenic properties of vascular smooth muscle are closely coupled to a functioning circulation.The electrical and mechanical oscillations, which can be traced back to rhythmic activity of the active electrogenic Na+K+ pump, could originate in the allosteric qualities of the enzyme phosphofructokinase (PFK).Thus, PFK represents a rhythmogenic enzyme which may serve as an example of the connection between the biological properties on a molecular level and the spatiotemporal system`s behavior.The cardiovascular system and its rhythmicity may be dominated by only a few control points, one of which is distinguished by the viscoelastic properties of a blood flow sensor macromolecule.Therefore, the three prominent control points PFK, (Na++K+)-ATPase and flow sensor conformation -acting as negatively feedback-couple nonlinear synergetic order papameter are sufficient to initiate the periodic events in the cardiovascular system and to provide a plausible explanation for their causal origin.
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