چكيده لاتين :
Background: Calcium overload and free radical mediated
damage in the mitochondria is the most important pathological
changes associated with myocardial ischemicreperfusion
injury. The verapamil post-treatment has been
previously reported to prevent reperfusion-induced myocardial
injury but functional recovery may be delayed due
to the drugיs inherent direct myocardial depression effect.
In the present study the effect of verapamil on mitochondrial
enzymes and sarcoplasmic ATPase system was examined
during the myocardial preconditioning and ischemic
reperfusion in rat heart.
Methods: Four groups of isolated rat hearts were perfused
with KH buffer in a retrograde manner by Lagendroff apparatus
. A time controlled ischemia, ischemic reperfusion and
classical precondition was produced by restoring the flow of
KH buffer in ischemic rat heart. The hearts were then processed
to isolate the mito chondria and sarcoplasmic reticulum
for the biochemical est imation.
Results: Mitochondrial enzyme and sarcoplasmic ATPase
activities were diminished in the ischemic period and further
decreased during reperfusion . However, preconditioning the
rat heart before the insult of ischemia and reperfusion improved
the enzyme activities. The preconditioning procedure
consisted of 4 cycles of 4 min. short ischemic periods followed
by 4 min. KH buffer perfusion applied before 30 min.
global ischemia and reperfusion caused an improvement in the
mitochondrial enzyme activities. On the other hand, sarcoplasmic
ATPase enzymes required a precondition procedure
of 7 cycles of 2 min. short ischemic periods followed by 2
min. reperfusion. The activities of the above enzymes were
improved further when verapamil was administered before the
insult of ischemic reperfusion.
Conclusion: This study shows the beneficial effect of classical
preconditioning with verapamil.
