A novel real-time servo-controlled perfusion system accurately reproduced arterial pressure waveforms and cogenerated physiological flow and shears for cultured vascular cells.
A novel in vitro perfusion system successfully replicates realistic mechanical pulsatile forces on vascular cells, enabling advanced studies of shear and distension interactions.
We developed a novel real-time servo-controlled perfusion system that exposes endothelial cells grown in nondistensible or distensible tubes to realistic pulse pressures and phasic shears at physiological mean pressures. A rate-controlled flow pump and linear servo-motor are controlled by digital proportional-integral-derivative feedback that employs previously digitized aortic pressure waves as a command signal. The resulting pressure mirrors the recorded waveform and can be digitally modified to yield any desired mean and pulse pressure amplitude, typically 0-150 mmHg at shears of 0.5-15 dyn/cm(2). The system accurately reproduces the desired arterial pressure waveform and cogenerates physiological flow and shears by the interaction of pressure with the tubing impedance. Rectangular glass capillary tubes 1-mm inside diameter (ID) are used for real-time fluorescent imaging studies (i. e., pH(i), NO, Ca(2+)), whereas silicon distensible tubes (4-mm ID) are used for more chronic (i.e., 2-24 h) studies regarding signal transduction and gene expression. The latter have an elastic modulus of 12.4. 10(6) dyn/cm(2) similar to in vivo vessels of this size and are studied with the use of a benchtop system. The new approach provides the first in vitro application of realistic mechanical pulsatile forces on vascular cells and should facilitate studies of phasic shear and distension interaction and pulsatile signal transduction.
Peng et al. (Fri,) reported a other. Real-time servo-controlled perfusion system was evaluated on Reproduction of desired arterial pressure waveform and cogeneration of physiological flow and shears. A novel real-time servo-controlled perfusion system accurately reproduced arterial pressure waveforms and cogenerated physiological flow and shears for cultured vascular cells.