slices by an inverted microscope. The chamber is made of Polycarbonate. It is
connected to a water bath to maintain constant temperature conditions. Two
incubation cells are positioned in the center of the chamber. The bottom of the
cells is sealed by glass, the cover is made of acrylic glass. The slices are fixed in
the incubation cells by positioning them under nylon strings fixed to a bent
platinum wire. The incubation cells can be filled with buffer, medium or drug
solutions through the filling pipe. Buffer solution can be removed from the cells
over a vacuum pipe. In addition, it is possible to gas the incubation cells in order
to use bicarbonate buffered media.
warmed to 37°C. The slices are screened for airways and transferred to the
incubation chamber. Lung slices are selected for study using predefined criteria
(Martin et al. 1996). Airways and vessels are focused, and finally the images are
analyzed by image analysis software (e.g., Optimas or Metamorph).
concentrations of endothelin-1. Shown is a lung slice containing an airway (B),
a pulmonary artery (PA) and a pulmonary vein (PV). The pulmonary artery and
the airway contracted almost completely, while the pulmonary vein area
decreased to only 50% of its initial area. These responses are now easily
quantified by digital imaging technique.
slices can be treated like a cell culture. Thus, the slices can be incubated
under various conditions and gene as well as protein expression or mediator
release be determined. In contrast to cell culture models, in slices the
anatomical structure of the lung is largely maintained, so that the functional
consequences of gene expression and mediator release can be evaluated.
Shown is one lung slice containing a small airway (B), a pulmonary artery (PA)
and a pulmonary vein (PV). The slice was imaged before (C) and after exposure to
increasing concentrations of endothelin-1, ranging from 10-10 M to 10-6 M.
functions under cell culture conditions. They can be prepared from nearly any
species including mouse, rat and human lungs. The method allows the study of
the response of airways of different size (down to the terminal bronchioles) and
to relate these changes in lung functions to gene expression and mediator
release. Slices are viable for at least three days. They can be placed under an
inverted microscope, where digital image techniques allow quantification not
only of the responsiveness of single airways, but also of single vessels. In
addition, it is possible to analyze the ciliary beating frequency. More than 20
slices can be obtained from one lung, thus this method is very economical in
terms of experimental costs and animal use. Tissue cores are prepared from the
lungs filled with agarose solution, after cooling to 4°C. From the cores, slices
(220 ± 20µm) are cut using a tissue slicer