Fig. 4. Tissue or plasma ascorbate versus ascorbate intake. A. Guinea pig. B. Plasma ascorbate versus ascorbate intake in men (light line and square symbols) and women (bold line and filled circles).C. aqueous ascorbate versus ascorbate intake in men (open squares) and women (filled circles). D. Lens ascorbate versus ascorbate intake in men (dashed lines and open squares) and women (solid line and filled circles). (A adapted from Berger J, Shepard D, Morrow F et al: Reduced and total ascorbate in guinea pig eye tissues in response to dietary intake. Curr Eye Res 7:681-86, 1988; B-D adapted from Taylor A, Jacques P, Nowell T Jr et al: Vitamin C in human and guinea pig aqueous, lens, and plasma in relation to intake. Curr Eye Res 16:857–864, 1997.)