a. Effect of haptoglobin addition (2, 10 and 20 μg per sample) on PLTP activity (5 min) of individual hyperlipidemic (H, n = 6) and normolipidemic (N, n = 2) plasma samples. From left to right: control, addition of 2 μg, 10 μg and 20 μg of Hp, respectively. One of two representative experiments with duplicate measurements per treatment. b. Effect of haptoglobin addition (2, 10 and 20 μg per sample) on PLTP activity (5 min) in hyperlipidemic plasma as a percentage of basal PLTP activity. Each plasma sample was analyzed in two independent experiments, with at least two replicates per experiment. The graph depicts the mean ± standard deviation of each group of six hyperlipidemic plasma (n = 6, p < 0.05). c. Ibidem, except that PLTP activity was analyzed after 60 min. d. Correlation between PLTP activity and Hp/Apo-A1 ratio in hyperlipidemic plasma samples with added haptoglobin (n = 11, Correlation coefficient -0.679, p < 0.05).