Arginine diet inhibits the

V_max of the Gardos channel activity in S+S-Antilles mouse red cells but does not change the EC₅₀. Gardos channel activity under oxygenated conditions was measured as described in “Materials and methods” on RBCs from mice on normal chow (Chow) and after 10 weeks on the 5% arginine diet (5% Arg). The clotrimazole-sensitive, calcium-activated K⁺ efflux was estimated from the difference between fluxes measured in the presence or absence of 10 μM clotrimazole. (A) TheV_max data shown represent the mean ± SE of assays performed in duplicate on 7 (normal chow) and 8 (5% arginine diet) different experiments on either individual mice or pooled blood from at least 2 mice (P < .04, t test). (B) The EC₅₀ data shown represent the mean ± SE of experiments performed in duplicate on 3 (normal chow) and 3 (5% arginine diet) different experiments on pooled blood from 3 different mice.