| Abstrakt: |
Abstract: We have used brain (dog, rat) and spinal cord (dog, rabbit) cell-free systems to study early postischaemic inhibition of protein synthesis. Ischaemia alone produced a relatively small decrease in activity of all subcellular systems used. When 15 min of normoxic reperfusion was used, more than 30 % decrease (p<0.01) in [¹⁴C]-leucine incoiporation was detected. A translational inhibitor that appeared in the postribosomal supernatant fraction at the early stage of reperfusion reduced translational capacity of an initiating cell-free system. It also phosphorylated the small (38 kDa) subunit of eukaryotic initiation factor 2 (eIF-2) in vitro. Effect of the inhibitor can be reversed by addition of partially purified intact eIF-2 and/or high concentration (2 mmol/1) of GTP. A prevention of postischaemic free oxygen radical formation by the reoxygenation with hypoxaer.Jc blood, containing 37.5 mm Hg O₂ at 0 - 5 min and 56 mm Hg at 6 - 10 min of recirculation, that was followed oy 5 min of normoxic reperfusion, resulted in a significant increase (p<0.02) of polypeptide chain synthesis in vitro when compared with normoxic reperfusion. |
