AJP - Heart and Circulatory Physiology, Vol 263, Issue 4 1243-H1249, Copyright © 1992 by American Physiological Society
PEG-SOD improves postischemic functional recovery and antioxidant status in blood-perfused rabbit hearts
Y. Qiu, M. Galinanes, R. Ferrari, A. Cargnoni, A. Ezrin and D. J. Hearse
Rayne Institute, St. Thomas' Hospital, London, United Kingdom.
The isolated blood-perfused rabbit heart, subjected to 60 min of
cardioplegic arrest and 60 min of reperfusion, was used to assess the
effects of polyethylene glycol-conjugated superoxide dismutase (PEG-SOD) on
postischemic recovery of left ventricular developed pressure (LVDP), the
tissue activity of SOD, and tissue redox state. The five groups studied
were the following: PEG-SOD-free control (group A), PEG-SOD as a
pretreatment and as an additive during cardioplegia and reperfusion (group
B), PEG-SOD as a pretreatment and a cardioplegic additive (group C),
PEG-SOD in cardioplegia alone (group D), and PEG-SOD in reperfusion alone
(group E). The results show that pretreatment with PEG-SOD improves
postischemic recovery of LVDP (72 +/- 2% and 66 +/- 7 vs. 47 +/- 4% in
groups B, C, and A, respectively). This protection was associated with an
improved tissue redox state. Thus the ischemia-induced rise in oxidized
glutathione was reduced from 313 +/- 26% (group A) to 162 +/- 15 and 138
+/- 14% (groups B and C, respectively), and the fall in reduced glutathione
was attenuated from 51 +/- 5% to 35 +/- 6 and 13 +/- 5%, respectively.
Tissue Mn-SOD activity was also conserved from 36 +/- 4% (group A) to 71
+/- 6 and 94 +/- 4% (groups B and C, respectively). No significant effect
was seen when PEG-SOD was applied in cardioplegia or during reperfusion
alone.
