ischaemic preconditioning of the human heart. - Leicester Research ...

2.5 Study groups
Three different studies were performed to investigateý (i) the stability of the preparation
(Study I ), (11) the effect of the severity of ischaernia (Study 2), and (ifi) the effect of the
duration of reoxygenation (Study 3).
In Study I (Figure 2.2), atnal slices (n=6/group) were subjected to various periods of
aerobic incubation after an initial 30 min equilibration period. At the end of the
experimental time, samples from the incubation media were taken for the assessment of
LDH leakage and the slices were removed for the determination of oxygen consumption,
tissue viability, nucleotide metabolite analysis and morphological examination.
Study 2 was divided into two parts. In study 2A (Figure 2.3A), slices (n=6/group) were
initially equilibrated for 30 min and then they were randomized to be subjected to
various periods of ischaemia (30,60 and 120 min) followed by 120 min of
rcoxygenation.
In Study 2B (see Figure 2.313), the slices were (n=6/group) randomly subjected to an
identical protocol of ischaernia and reoxygenation as that in Study 2A with the only
exception being that they were incubated aerobically for 24 hr before they were
subjected to ischaemia and reoxygenation. At the end of the experimental time, samples
from the incubation media were taken for the measurement of LDH leakage and the
slices were taken for the determination of tissue viability in both Study 2A and Study
2B. In addition, oxygen consumption of the slices was assessed in study 2A only.
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