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A mathematical model of vasoreactivity in rat mesenteric arterioles: I. Myoendothelial communication
Author(s) -
Kapela Adam,
Bezerianos Anastasios,
Tsoukias Nikolaos M.
Publication year - 2009
Publication title -
microcirculation
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.793
H-Index - 83
eISSN - 1549-8719
pISSN - 1073-9688
DOI - 10.3109/10739680903177539
Subject(s) - biophysics , hyperpolarization (physics) , stimulation , calcium , chemistry , nitric oxide , membrane potential , endothelium , biology , microbiology and biotechnology , anatomy , endocrinology , stereochemistry , organic chemistry , nuclear magnetic resonance spectroscopy
To study the effect of myoendothelial communication on vascular reactivity, we integrated detailed mathematical models of Ca 2+ dynamics and membrane electrophysiology in arteriolar smooth muscle (SMC) and endothelial (EC) cells. Cells are coupled through the exchange of Ca 2+ , Cl − , K + , and Na + ions, inositol 1,4,5‐triphosphate (IP 3 ), and the paracrine diffusion of nitric oxide (NO). EC stimulation reduces intracellular Ca 2+ ([Ca 2+ in the SMC by transmitting a hyperpolarizing current carried primarily by K + . The NO‐independent endothelium‐derived hyperpolarization was abolished in a synergistic‐like manner by inhibition of EC SK Ca and IK Ca channels. During NE stimulation, IP 3 diffusing from the SMC induces EC Ca 2+ release, which, in turn, moderates SMC depolarization and [Ca 2+ ] i elevation. On the contrary, SMC [Ca 2+ ] i was not affected by EC‐derived IP 3 . Myoendothelial Ca 2+ fluxes had no effect in either cell. The EC exerts a stabilizing effect on calcium‐induced calcium release‐dependent SMC Ca 2+ oscillations by increasing the norepinephrine concentration window for oscillations. We conclude that a model based on independent data for subcellular components can capture major features of the integrated vessel behavior. This study provides a tissue‐specific approach for analyzing complex signaling mechanisms in the vasculature.