[Changes and significance of PAO activities and polyamine levels at different time of reperfusion after transient focal cerebral ischemia in rats].

OBJECTIVE

To assay the changes of polyamine oxidase (PAO) activities and polyamine levels in the cortex and subcortex at different time of reperfusion following 2 h focal cerebral ischemia in rats in order to explore the regularity and signifiance ofh these changes.

METHODS

Rats of 2 h reversible focal cerebral ischemia were produced by ameliorated method of Longa's intraluminal suture occlusion of middle cerebral artery (MCA). PAO activities and polyamine levels in the cortex and subcortex were measured by homovanillic acid fluorometry and high-performance liquid chromatograph (HPLC) after 2, 4, 8, and 24 h reperfusion following 2 h ischemia, respectively.

RESULTS

PAO activity of the experimental group increased after 8 h reperfusion (P < 0.01). The peak value of PAO activity appeared after 24 h reperfusion (P < 0.01). Putrescine level of the experimental group was elevated after 4 h reperfusion (P < 0.05), and the peak value of putrescine appeared after 24 h reperfusion (P < 0.05). Spermidine and spermine levels of 8, 24 h reperfusion in the experiment group decreased significantly c eompared with the control group (P < 0.05).

CONCLUSION

PAO activities increased significantly after reperfusion following transient focal cerebral ischemia, which promoted the later peak production of putrescine. It may be contributed to the brain damage after cerebral ischemia.