Περίληψη:
Although ischaemic preconditioning (PC) has been shown to protect normal
hearts from a subsequent ischaemic insult, its protective effect on the
hypertrophied myocardium has not been widely studied. This study was
designed to investigate whether ischaemic preconditioning protects
hearts with hypertrophy (HYP). Cardiac HYP was produced in rats by
suprarenal abdominal aortic constriction of 5 weeks’ duration, and was
defined as left ventricular weight: body weight [LVW: BW(mg/g)] ratio
over 3.0. Isolated rat hearts were perfused with a modified
Krebs-Henseleit buffer at 37 degrees C in a Langendorff preparation.
Hearts from sham-operated animals (NORM) and those with HYP underwent a
PC protocol consisting of 3 min of global zero flow ischaemia, 5 min of
reperfusion followed by 5 min of ischaemia and 5 min of reperfusion.
This was followed by 20 min ischaemia and 45 min reperfusion. Control
hearts in the HYP and NORM groups were not subjected to the PC protocol.
There were, thus, four experimental groups: NORM control (n = 9), NORM,
PC (n = 9), HYP control (n = 9), HYP, PC (n = 11). The recovery of
function after ischaemia was evaluated by recovery of left ventricular
developed pressure (LVDP) expressed as % of the initial value (LVDP%).
The LVW: BW ratio for the HYP groups was 3.4 (SEM 0.08). LVDP% was
higher (p < 0.01) in preconditioned groups as compared with controls. In
NORM control recovery was 49.3 (6.1), NORM, PC 76.5 (3.4), HYP control
39.8 (4.6) HYP, PC 70.1 (4.1). These data indicate that the ability of
preconditioning to protect against ischaemic ventricular dysfunction is
preserved in this model of cardiac hypertrophy.
Συγγραφείς:
Pantos, CI
Davos, CH
Carageorgiou, HC
Varonos, DV and
Cokkinos, DV
