Fig. 5. The ouabain-insensitive Na influx in air-equilibrated red blood cells (RBCs) measured during the initial 5 min at a saline pH of (A) 7.97 or (B) 7.03 in unstimulated RBCs (basal) with or without 10^–4 mol l^–1 amiloride, or RBCs stimulated by 10^–5 mol l^–1 isoproterenol alone or together with 10^–4 mol l^–1 amiloride. Values are means ± s.d. A significant difference (P<0.05) from the respective isoproterenol-stimulated Na influx is indicated by ^*. N=5.