Fig. (7) Time-dependent effects of CPA on the activity of distinct NOS isoforms of platelet. Activity measurements were performed as described in Materials and Methodology and assessed by RNS accumulation in vitro after long-term incubation of platelet isolated from blood of control rats (1) and CPA-treated rats sacrificed 9 days (2) and 18 days (3) after final treatment. Stimulatory effect of exogenous arginine and NOS cofactors on both iNOS and cNOS of platelet observed for conrol rats was restored in CPA-treated rats in 18 days pt. Values are means ± S.E.M. P<0.05 compared with control.