Background: To investigate the effects of tissue-type plasminogen activator (tPA) gene transfer with left-atrium local positioning on the fibrinolytic activity of rabbit left atrial blood.
Methods: A total of 48 rabbits were randomly divided into 3 groups (n = 16): gene therapy, vector control, and blank control groups. Each group was divided into 2 subgroups (8 rabbits in each subgroup) according to the sacrifice time on the postoperative 3(rd) and 14(th) days. The tPA mRNA transcriptional level and exogenous tPA protein expression within regional myocardial tissues of the left atrium were detected on the postoperative 3(rd) and 14(th) days. After excluding the animals that died, 6 samples of each subgroup were randomly selected for the statistics (n = 6).
Results: The tPA activities in rabbit left atrial blood and peripheral blood were also detected. The tPAmRNA and tPA protein expressions within regional myocardial tissues were detected on the postoperative 3(rd) and 14(th) days. The tPA activity in left atrial blood in the gene therapy group was higher than the tPA activity of other groups (p < 0.02). No significant differences were observed in the tPA activity of peripheral blood among the 3 groups before surgery. A gelatin-coated Dacron piece, which carried the tPA gene, was implanted in the left atrial appendage.
Conclusions: The gelatin-coated Dacron piece could express and secrete tPA proteins in the region, thus enhancing the fibrinolytic activity of left atrial blood.
Key words: Fibrinolytic activity; Gelatin coating; Gene; Left atrium; Tissue-type plasminogen activator.