[Effect of chronic epaden administration on the tissue plasminogen activator activity in rabbits]

The chronic oral administration of epaden (a concentrate of n-3 polyunsaturated fatty acids, n-3 PUFA) to rabbits leads to a decrease in activity of the tissue type plasminogen activator (t-PA) in the blood plasma. In order to elucidate the mechanism of this phenomenon, the epinephrine (adrenaline) stimulated t-PA release in rabbits pretreated with epaden for 4 weeks was compared to that in the control (untreated) group. The epinephrine injections led to a reliable, albeit short-time, increase in the t-PA activity in both test and control groups. Although the base activity of t-PA in the epaden-treated group was lower than that in the control group, the t-PA release in the former group was more pronounced. In addition, the t-PA production was induced by the immobilization shock model in rabbits one month after beginning of the epaden administration (animals in the control group were subject to the shock without epaden pretreatment). In this test, the t-PA release was also more intense in the epaden-treated animals. These results indicate that the dietary epaden administration per os reduces the basal t-PA level, but increases the agonist-induced plasminogen activator production.