Total fat content of diets. Marckmann et al. found in both a short term (2 week) and a longer term trial (8months) that plasma euglobulin fibrinolytic capacity and plasma t-PA activity were increased on low-fat/high fiber diets as compared with high-fat/low fiber diets (fig 17) .No changes were observed in t-PA and PAI-I antigen concentration. In agreement with these results, Mehrabian et al. reported decreased plasminogen and PAI-I activities ,after consumption of a low-fat/high-fiber/low-cholesterol dier with less than 10% of energy from fat for 21 days. This was associated with decreased 1-PA antigen concentrations. However. from these studies it is not possible to conclude whether the changes observed were due to the lower fat or cholesterol contents. or the higher fiber content of the diets.