Sensitivity of plasma FV to APC in mice.

Plasma was collected from CBS^+/+ mice (A) or CBS^+/− mice (B) fed a control diet (solid circles), a high-methionine diet (open triangles), or a high-methionine/low-folate diet (open squares). Samples were diluted 1:10 in human FV–deficient plasma, and APTT was measured in the presence of the indicated concentrations of human APC. Values are mean ± SE.