FIGURE 9.

Comparison of inhibition of GMPMT and glycogen phosphorylase by glycogen phosphorylase inhibitors, isofagomine and DIA. Incubations for measuring activity of glycogen phosphorylase were as described in Fig. 8 but contained various amounts of either isofagomine (A) or DIA (B). Incubations for measuring activity of GMPMT were as described in Fig. 8 but also contained various amounts of either isofagomine (A) or DIA (B). A, glycogen phosphorylase (■) activity and GMPMT (□) activity was measured and compared in the presence of various amounts of isofagomine. B, both glycogen phosphorylase (■) and GMPMT (□) were assayed in the presence of increasing amounts of DIA.