ASPIRIN EFFECT ON PLATELET ANTIPLASMINS PRELEASE

It was shown platelet antiplasmin activity which is released by col 1anen(Col)and thrombin, probably associated with a-oran u 1 es . Lys i s area produced by eunl obul i ns (eun) of PPP and PRP whether or not previously treated with ADP(5uM), Col(20ug/ml) and aspirin(ASA)(00up/nl)in plas-mi nooen- f ree-f i bri n plates were s tudi ed. Res u 1 ts (mm² ) were:eunPPP:151.3±39.8;+ADP:155.7±47;+Co1: 155.5±150.8; + ASA: 160±142. -EugPRP: 142*42;+ADP: 145*72;+Col : 136*43 ; -⋋ASA: 138+47.-EugPRP produced slightly lower lysis area than euaPPP(p:ns).ADP , Co 1 and ASA neither modify the lysis area of eugPPP nor of eugPRP.Washed piatelets(WP)whether or not treated with ASA were resuspended in eu^PPP and then treated with Co 1 ( 2 and 20ug/ml ). Resul ts (mm² )were : euoPPP:109.8+35;+3xl05WP/ul:66.4±24;+106WP/u1:63±17;+2x lO WP/ul:58.4±13.- Wi th Col(20ug/ml):euoPPP:101.3±28; + 3xl05WP/ul:48.4±14; + 10cWP/ul :46.2±16;+2xl06WP/ul :44.5± i2;+ 2x106WP/u1+ ASA:45.2±8.-With Col(2ug/nl):eugPPP:10 3± 25;+2xl06WP/ul : 49±10 ;+2x1 Of>WP/ul+AS A: 50 . 9±13 . WP in eug PPPshowed lower lysis area than eugPPP(d<0.00 1). The higher number of piatelets ,the lower lysis area.Col-treated WP showed greater inhibition of lysis area than non-treated WP.ASA could not inhibit this effect

Conclusion:In euoPRP there was a slioht antiplasmin activity related with platelets not comoletely eliminated from eug fractionation.WP in euoPPP showed hioher antiplasmin activity.High and low doses of Col produced antiplasmin release.ASA could not inhibit its release with both doses of Col.We must consider the possibility that platelet antiplasmins could be released by different metabolic pathways other than cycl oox.ygenase way or they are not stored in the a-granules.