(Downloading may take up to 30 seconds.
If the slide opens in your browser, select File -> Save As to save it.)
Click on image to view larger version.

Fig. 1. Protocols used in Experiment 1. Hearts were exposed to one of four
treatments: (A) control, (B) 5 min of severe hypoxia, (C) 30 min of severe
hypoxia or (D) 5 min of severe hypoxia (preconditioning) followed by 30 min of
severe hypoxia. The solid line represents the pressure development of the
ventricle as determined by the height of the output pressure
(POUT) head, which was set to either a physiologically
relevant level of 5.0 kPa, or a sub-physiological level of 1.0 kPa. The arrows
mark the initial cardiac stretch, where input pressure
(PIN) was raised to elicit a cardiac output
(
) of 30 ml min-1
kg-1. The bold steps mark the maximum cardiac output tests
(
max), where
PIN was raised sequentially from 0.3 kPa to 0.4 kPa, and
finally to 0.45 kPa. The shaded rectangles represent periods of severe hypoxia
(PO2=510 mmHg). During hypoxia,
PIN was not adjusted and
was allowed to fall. During all
periods of oxygenated cardiac perfusion,
was maintained at a physiologically
resting level of 16 ml min-1 kg-1, by adjusting
PIN as needed.