Fig. 6.

Hypothetical sources of cellular cyanate with access to T. spiralis. Potential sources of cyanate are designated by dashed lines as are mechanisms for [A] depleting cellular arginine via nutrient flux into macrophages or [B] liberating macrophage-derived arginase into the cell cytoplasm to control arginine concentration. Mechanisms are based upon a pseudo-urea cycle which has been demonstrated in muscle cells. Enzymes facilitating such a cycle are designated as CPS1 = Carbamoyl Phosphate Synthetase 1; OTC = Ornithine Transcarbamylase; AS = Argininosuccinate Synthetase; AL = Argininosuccinate Lyase; NOS = Nitric Oxide Synthase; ARG = Arginase 1. Pi = inorganic phosphate. The rete is presumed to envelop the entire NC.